fix javadoc

Signed-off-by: Michael Hirsch <michael.hirsch@bosch-si.com>

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/Constants.java

@@ -9,7 +9,6 @@
 package org.eclipse.hawkbit.repository;
 
 import org.eclipse.hawkbit.repository.model.ActionStatus;
-import org.eclipse.hawkbit.repository.model.Target;
 
 /**
  * Repository constants.
@@ -19,8 +18,8 @@ public final class Constants {
 
     /**
      * Prefix that the server puts in front of
-     * {@link ActionStatus#getMessages()} is the comments was generated by it
-     * and not be thy {@link Target}.
+     * {@link ActionStatus#getMessages()} if the message is generated by the
+     * server.
      */
     public static final String SERVER_MESSAGE_PREFIX = "Update Server: ";