Tweak plus and minus svg icons

Shrink them a tiny bit so they look the same size as cross.

* etc/images/symbols/minus_16.svg:
* etc/images/symbols/plus_16.svg: Shrink a bit.
10 jobs for master in 236 minutes and 4 seconds (queued for 6 seconds)
Status Job ID Name Coverage
  Build Images
failed #78046
build-image-inotify

02:49:09

 
  Normal
skipped #78047
test-all-inotify
 
  Platform Images
failed #78048
build-image-eglot

02:46:52

failed #78050
build-image-gnustep

00:50:54

failed #78049
build-image-tree-sitter

02:46:51

 
  Platforms
skipped #78051
test-eglot
skipped #78053
test-gnustep
skipped #78052
test-tree-sitter
 
  Native Comp Images
passed #78054
build-native-comp-speed2

02:53:55

 
  Native Comp
failed #78055
test-native-comp-speed2

01:01:44

 
Name Stage Failure
failed
test-native-comp-speed2 Native Comp
Uploading artifacts for failed job
Uploading artifacts...
test-native-comp-speed2-83dfdac0/: found 538 matching files and directories

Uploading artifacts as "archive" to coordinator... 201 Created
id=78055 responseStatus=201 Created token=9aUqETGB
Uploading artifacts...
test-native-comp-speed2-83dfdac0/junit-test-report.xml: found 1 matching files and directories

Uploading artifacts as "junit" to coordinator... 201 Created
id=78055 responseStatus=201 Created token=9aUqETGB
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 2

failed
build-image-inotify Build Images
ef33a8d8f4d4: Retrying in 2 seconds
ef33a8d8f4d4: Retrying in 1 second
net/http: request canceled (Client.Timeout exceeded while awaiting headers)
Running after script...
$ test -n "$(docker ps -aq -f name=${test_name})" && docker cp ${test_name}:checkout/test ${test_name}
$ test -n "$(docker ps -aq -f name=${test_name})" && docker rm ${test_name}
$ find ${test_name} ! \( -name "*.log" -o -name ${EMACS_TEST_JUNIT_REPORT} \) -type f -delete
find: build-image-inotify-83dfdac0: No such file or directory
ERROR: Job failed: exit code 1
failed
build-image-tree-sitter Platform Images
6c49927c44ab: Retrying in 6 seconds
6c49927c44ab: Retrying in 5 seconds
net/http: request canceled (Client.Timeout exceeded while awaiting headers)
Running after script...
$ test -n "$(docker ps -aq -f name=${test_name})" && docker cp ${test_name}:checkout/test ${test_name}
$ test -n "$(docker ps -aq -f name=${test_name})" && docker rm ${test_name}
$ find ${test_name} ! \( -name "*.log" -o -name ${EMACS_TEST_JUNIT_REPORT} \) -type f -delete
find: build-image-tree-sitter-83dfdac0: No such file or directory
ERROR: Job failed: exit code 1
failed
build-image-eglot Platform Images
context deadline exceeded (Client.Timeout exceeded while awaiting headers)
Running after_script
Running after script...
$ test -n "$(docker ps -aq -f name=${test_name})" && docker cp ${test_name}:checkout/test ${test_name}
$ test -n "$(docker ps -aq -f name=${test_name})" && docker rm ${test_name}
$ find ${test_name} ! \( -name "*.log" -o -name ${EMACS_TEST_JUNIT_REPORT} \) -type f -delete
find: build-image-eglot-83dfdac0: No such file or directory
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1

failed
build-image-gnustep Platform Images
executor failed running [/bin/sh -c make bootstrap]: exit code: 2
Running after_script
Running after script...
$ test -n "$(docker ps -aq -f name=${test_name})" && docker cp ${test_name}:checkout/test ${test_name}
$ test -n "$(docker ps -aq -f name=${test_name})" && docker rm ${test_name}
$ find ${test_name} ! \( -name "*.log" -o -name ${EMACS_TEST_JUNIT_REPORT} \) -type f -delete
find: build-image-gnustep-83dfdac0: No such file or directory
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1