publish mqtt emsesp on-change messages on connect

src/core/temperaturesensor.cpp

@@ -473,10 +473,15 @@ void TemperatureSensor::publish_values(const bool force) {
         return;
     }
 
-    if (force && Mqtt::publish_single()) {
+    if (force) {
+        if (Mqtt::publish_single()) {
         for (const auto & sensor : sensors_) {
             publish_sensor(sensor);
         }
+            return;
+        } else if (!EMSESP::mqtt_.get_publish_onchange(0)) {
+            return; // wait for first time periode
+        }
     }
 
     JsonDocument doc;