TimeService: do no use NTP if we are using cellular connection

Author: pennam

Diff for: src/utility/time/TimeService.cpp

@@ -292,9 +292,11 @@ unsigned long TimeServiceClass::getRemoteTime()
      * This is the most reliable time source and it will
      * ensure a correct behaviour of the library.
      */
-    unsigned long const ntp_time = NTPUtils::getTime(_con_hdl->getUDP());
-    if(isTimeValid(ntp_time)) {
-      return ntp_time;
+    if(_con_hdl->getInterface() != NetworkAdapter::CELL) {
+      unsigned long const ntp_time = NTPUtils::getTime(_con_hdl->getUDP());
+      if(isTimeValid(ntp_time)) {
+        return ntp_time;
+      }
     }
 
     /* As fallback if NTP request fails try to obtain the