fix: timedatectl not available in docker container

tests/system-test/2-query/timezone.py

@@ -15,8 +15,16 @@ class TDTestCase:
     def run(self):  # sourcery skip: extract-duplicate-method
         tdSql.prepare()
         # get system timezone
-        time_zone = os.popen('timedatectl | grep zone').read(
-        ).strip().split(':')[1].lstrip()
+        time_zone_arr = os.popen('timedatectl | grep zone').read(
+        ).strip().split(':')
+        if len(time_zone_arr) > 1:
+            time_zone = time_zone_arr[1].lstrip()
+        else:
+            # possibly in a docker container
+            time_zone_1 = os.popen('ls -l /etc/localtime|awk -F/ \'{print $(NF-1) "/" $NF}\'').read().strip()
+            time_zone_2 = os.popen('date "+(%Z, %z)"').read().strip()
+            time_zone = time_zone_1 + " " + time_zone_2
+            print("expected time zone: " + time_zone)
 
         tdLog.printNoPrefix("==========step1:create tables==========")
         tdSql.execute(