修复bug

common/src/main/java/com/xypower/common/MicroPhotoContext.java

@@ -55,6 +55,9 @@ public class MicroPhotoContext {
         public int separateNetwork;
 
         public String getUrl() {
+            if (TextUtils.isEmpty(server)) {
+                return "";
+            }
             return "http://" + server + ":" + Integer.toString(port);
         }
     }