Add fallback in case the contact does not have a name

Basically set the phoneNumber as name as it was before this change.

REVIEW: 127297

src/org/kde/kdeconnect/Plugins/TelephonyPlugin/TelephonyPlugin.java

@@ -106,6 +106,8 @@ public class TelephonyPlugin extends Plugin {
 
         if (contactInfo.containsKey("name")) {
             np.set("contactName", contactInfo.get("name"));
+        } else {
+            np.set("contactName",  phoneNumber);
         }
 
         if (contactInfo.containsKey("photoID")) {