filer.copy: use filer settings, avoid unnecessary command line options

fix https://github.com/chrislusf/seaweedfs/issues/968

other/java/client/src/main/proto/filer.proto

@@ -39,6 +39,9 @@ service SeaweedFiler {
     rpc Statistics (StatisticsRequest) returns (StatisticsResponse) {
     }
 
+    rpc GetFilerConfiguration (GetFilerConfigurationRequest) returns (GetFilerConfigurationResponse) {
+    }
+
 }
 
 //////////////////////////////////////////////////
@@ -205,3 +208,12 @@ message StatisticsResponse {
     uint64 used_size = 5;
     uint64 file_count = 6;
 }
+
+message GetFilerConfigurationRequest {
+}
+message GetFilerConfigurationResponse {
+    repeated string masters = 1;
+    string replication = 2;
+    string collection = 3;
+    uint32 max_mb = 4;
+}