utime.h: fix timezone issue in round_to_* funcs.

gmtime_r converts local time to UTC, however mktime only takes an
argument as local time. Use localtime_r instead of gmtime_r will fix.

Fixes: #14862

Reported-by: isyippee <yippee_liu@163.com>
Signed-off-by: Zhao Chao <zhaochao1984@gmail.com>
(cherry picked from commit c914f28)

src/include/utime.h

@@ -148,7 +148,7 @@ class utime_t {
   utime_t round_to_minute() {
     struct tm bdt;
     time_t tt = sec();
-    gmtime_r(&tt, &bdt);
+    localtime_r(&tt, &bdt);
     bdt.tm_sec = 0;
     tt = mktime(&bdt);
     return utime_t(tt, 0);
@@ -157,7 +157,7 @@ class utime_t {
   utime_t round_to_hour() {
     struct tm bdt;
     time_t tt = sec();
-    gmtime_r(&tt, &bdt);
+    localtime_r(&tt, &bdt);
     bdt.tm_sec = 0;
     bdt.tm_min = 0;
     tt = mktime(&bdt);