(woman2-TH): Quote search string argument to string-match.

lisp/woman.el

@@ -3846,10 +3846,9 @@ v alters page foot left; m alters page head center.
       (insert " -- ")
       (woman-forward-arg 'unquote 'concat)
       ;; Delete repeated arguments:
-      (if (string-match (buffer-substring here (point))
+      (if (string-match (regexp-quote (buffer-substring here (point)))
 			(buffer-substring start here))
-	  (delete-region here (point)))
-      ))
+	  (delete-region here (point)))))
   ;; Embolden heading (point is at end of heading):
   (woman-set-face
    (save-excursion (beginning-of-line) (point)) (point) 'woman-bold)