Report temperatures for all extruders

Marlin/Marlin_main.cpp

@@ -1220,6 +1220,14 @@ void process_commands()
           SERIAL_PROTOCOL_F(degTargetBed(),1);
         #endif //TEMP_BED_PIN
       #else
+        for (int8_t cur_extruder = 0; cur_extruder < EXTRUDERS; ++cur_extruder) {
+          SERIAL_PROTOCOLPGM(" T");
+          SERIAL_PROTOCOL(cur_extruder);
+          SERIAL_PROTOCOLPGM(":");
+          SERIAL_PROTOCOL_F(degHotend(cur_extruder),1); 
+          SERIAL_PROTOCOLPGM(" /");
+          SERIAL_PROTOCOL_F(degTargetHotend(cur_extruder),1); 
+        }
         SERIAL_ERROR_START;
         SERIAL_ERRORLNPGM(MSG_ERR_NO_THERMISTORS);
       #endif