attempt to fix syntax error in unicode check

Looks like builds were always failing, even when unicode wasn't found in the diff. I'm trying to fix this by adding the missing 'fi' at the end of the if statement.

 * #90 (comment)

Author: maltfield

.github/workflows/unicode_warn.yml

@@ -133,5 +133,6 @@ jobs:
           exit 1
         else
           exit 0
+        fi
 
       shell: bash {0}