use default dns if no records in preferences

Author: Cenmrev

V2RayX/ServerProfile.m

@@ -60,7 +60,10 @@ - (NSDictionary*)v2rayConfigWithLocalPort:(NSInteger)localPort
     if ([self.useMkcp boolValue] == true) {
         config[@"outbound"][@"streamSettings"] = @{@"network": @"kcp"};
     }
-    config[@"dns"][@"servers"] = [[[NSUserDefaults standardUserDefaults] objectForKey:@"dns"] componentsSeparatedByString:@","];
+    NSArray* dnsArray = [[[NSUserDefaults standardUserDefaults] objectForKey:@"dns"] componentsSeparatedByString:@","];
+    if ([dnsArray count] > 0) {
+        config[@"dns"][@"servers"] = dnsArray;
+    }
     return config;
 }