patch 9.1.0588: The maze program no longer compiles on newer clang

Problem:  The maze program no longer compiles on newer clang
Solution: Use ANSI C function definition for main()
          (Mohamed Akram)

Implicit int is an error in newer versions of clang.

closes: #15247

Signed-off-by: Mohamed Akram <mohd.akram@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 9ce9c8f..e97346d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    588,
+/**/
     587,
 /**/
     586,