patch 8.2.0173: build fails with old compiler

Problem:    Build fails with old compiler.
Solution:   Do not use anonymous unions. (John Marriott)
diff --git a/src/version.c b/src/version.c
index 936f9b5..33fe21c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -743,6 +743,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    173,
+/**/
     172,
 /**/
     171,