patch 8.1.0194: possibly use of NULL pointer

Problem:    Possibly use of NULL pointer. (Coverity)
Solution:   Reset the re_in_use flag earlier.

src/version.c

@@ -789,6 +789,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    194,
 /**/
     193,
 /**/