Fix documentation of 'eudc-inline-expansion-format'

* doc/misc/eudc.texi (Inline Query Expansion): Fix the default value of
'eudc-inline-expansion-format'. (Bug#24840)

Backport:

(cherry picked from commit 1fef1387)

doc/misc/eudc.texi

@@ -733,8 +733,7 @@ upon an inline expansion request.  It is a list whose first element is a
 string passed to @code{format}.  Remaining elements are symbols
 corresponding to directory attribute names.  The corresponding attribute
 values are passed as additional arguments to @code{format}.  Default is
-@code{("%s" email)} but you may want to consider a value like @code{("%s
-<%s>" name email)}
+@code{("%s %s <%s>" firstname name email)}.
 @end defvar
 
 @defvar eudc-multiple-match-handling-method