patch 8.2.0594: MS-Windows: cannot build with WINVER set to 0x0501

Problem:    MS-Windows: cannot build with WINVER set to 0x0501.
Solution:   Only use inet_ntop() when available. (Ozaki Kiichi, closes #5946)
diff --git a/src/version.c b/src/version.c
index c3a0a19..09dc678 100644
--- a/src/version.c
+++ b/src/version.c
@@ -747,6 +747,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    594,
+/**/
     593,
 /**/
     592,