patch 9.1.0776: test_strftime may fail because of missing TZ data

Problem:  test_strftime may fail because of missing TZ data
Solution: Use GMT offsets to validate timezone differences (James McCoy)

Some systems only provide timezones that follow the geographical region
naming (e.g. America/New_York) by default and require an additional
install for other names (like EST).

The GMT+<offset> format must always be honored, so use that to generate
distinct data for the test.

closes: #15848

Signed-off-by: James McCoy <jamessan@jamessan.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 01acbe7..5dbd500 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    776,
+/**/
     775,
 /**/
     774,