patch 8.2.5125: MS-Windows: warnings from MinGW compiler

Problem:    MS-Windows: warnings from MinGW compyler.
Solution:   Use "volatile". (Yasuhiro Matsumoto, closes #10589)  Initialize
            variable.
diff --git a/src/version.c b/src/version.c
index 66dba17..82ac4ea 100644
--- a/src/version.c
+++ b/src/version.c
@@ -735,6 +735,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    5125,
+/**/
     5124,
 /**/
     5123,