patch 8.2.3378: MS-Windows: completing environment variables with % is wrong

Problem:    MS-Windows: completing environment variables with % is wrong.
Solution:   Only complete environment variables with $. (Albert Liu,
            closes #8791)
diff --git a/src/version.c b/src/version.c
index 7aa602f..a3f0a8d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -756,6 +756,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    3378,
+/**/
     3377,
 /**/
     3376,