fix(os): Ubuntu 18.04 timezone error.

source/os/src/osTimezone.c

@@ -172,6 +172,13 @@ void taosGetSystemTimezone(char *outTimezoneStr, enum TdTimezone *tsTimezone) {
            -timezone / 3600);
 #else
 
+  char  buf[4096] = {0};
+  char *tz = NULL;
+  {
+    int n = readlink("/etc/localtime", buf, sizeof(buf));
+    if (n < 0) {
+      printf("read /etc/localtime error, reason:%s", strerror(errno));
+      
       if (taosCheckExistFile("/etc/timezone")) {
         /*
         * NOTE: do not remove it.
@@ -228,12 +235,8 @@ void taosGetSystemTimezone(char *outTimezoneStr, enum TdTimezone *tsTimezone) {
         */
         snprintf(outTimezoneStr, TD_TIMEZONE_LEN, "%s (%s, %s%02d00)", buf, tzname[daylight], tz >= 0 ? "+" : "-", abs(tz));
       } else {
-    char  buf[4096] = {0};
-    char *tz = NULL;
-    {
-      int n = readlink("/etc/localtime", buf, sizeof(buf));
-      if (n < 0) {
-        printf("read /etc/localtime error, reason:%s", strerror(errno));
+        printf("There is not /etc/timezone.\n");
+      }
       return;
     }
     buf[n] = '\0';
@@ -272,6 +275,5 @@ void taosGetSystemTimezone(char *outTimezoneStr, enum TdTimezone *tsTimezone) {
   */
   snprintf(outTimezoneStr, TD_TIMEZONE_LEN, "%s (%s, %+03ld00)", tz, tm1.tm_isdst ? tzname[daylight] : tzname[0],
           -timezone / 3600);
-  }
 #endif
 }