patch 8.1.2186: error for bad regexp even though regexp is not used

Problem:    Error for bad regexp even though regexp is not used, when writing
            a file. (Arseny Nasokin)
Solution:   Ignore regexp errors. (closes #5059)

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2186,
 /**/
     2185,
 /**/