tests: test-gendoc.t checks if anything was translated

This would triggered when the variable would be set wrong again.

tests/test-gendoc.t

@@ -11,6 +11,10 b' Test document extraction'
   >     echo "" >> gendoc-$LOCALE.txt
   >     LANGUAGE=$LOCALE python "$TESTDIR/../doc/gendoc.py" >> gendoc-$LOCALE.txt 2> /dev/null || exit
   > 
+  >     if [ $LOCALE != C ]; then
+  >         cmp -s gendoc-C.txt gendoc-$LOCALE.txt && echo '** NOTHING TRANSLATED **'
+  >     fi
+  > 
   >     # We call runrst without adding "--halt warning" to make it report
   >     # all errors instead of stopping on the first one.
   >     echo "checking for parse errors"