Continue to poll for config changes after startup.

service/src/main/java/org/whispersystems/textsecuregcm/storage/DynamicConfigurationManager.java

@@ -73,6 +73,7 @@ public class DynamicConfigurationManager {
     }
 
     new Thread(() -> {
+      while (true) {
         try {
           retrieveDynamicConfiguration().ifPresent(configuration::set);
         } catch (Throwable t) {
@@ -80,6 +81,7 @@ public class DynamicConfigurationManager {
         }
 
         Util.sleep(5000);
+      }
     }).start();
   }