patch 8.1.0604: autocommand test fails on MS-Windows

Problem:    Autocommand test fails on MS-Windows.
Solution:   Use pathcmp() instead of strcmp() to check if a directory differs.

src/version.c

@@ -799,6 +799,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    604,
 /**/
     603,
 /**/