patch 8.1.1500: wrong shell command when building with VIMDLL and "!" in 'go'

Problem:    Wrong shell command when building with VIMDLL and "!" in
            'guioptions'.
Solution:   Add check for GUI in use. (Ken Takata)
diff --git a/src/misc2.c b/src/misc2.c
index 45070d7..47b3c72 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -3253,7 +3253,11 @@
 
 	if (cmd == NULL || *p_sxq == NUL
 #if defined(FEAT_GUI_MSWIN) && defined(FEAT_TERMINAL)
-		|| vim_strchr(p_go, GO_TERMINAL) != NULL
+		|| (
+# ifdef VIMDLL
+		    gui.in_use &&
+# endif
+		    vim_strchr(p_go, GO_TERMINAL) != NULL)
 #endif
 		)
 	    retval = mch_call_shell(cmd, opt);