follow-up to r5356 - fixed skip via atlocal_win

Author: sf-mensch

tests/atlocal_win

@@ -126,7 +126,7 @@ set_utf8_locale () {
 # Note: we explicit do not set COB_ON_CYGWIN here,
 # as this is file is about running non-cygwin binaries
     # Windows but not Cygwin
-    COB_ON_WINDOWS=1
+    COB_ON_WINDOWS=yes
     export COB_ON_WINDOWS
 
 # Fix for testcases where cobc uses win32 paths internally