patch 8.2.4754: using cached values after unsetting some environment variables

Problem:    Still using cached values after unsetting some known environment
            variables.
Solution:   Take care of the side effects. (closes #10194)

src/version.c

@@ -746,6 +746,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4754,
 /**/
     4753,
 /**/