!4355 issue修复：开启uppercase_attribute_name参数后，gs_dump导出失败问题修复

Merge pull request !4355 from zhangzhixian/master

src/bin/pg_dump/pg_dump.cpp

@@ -826,8 +826,6 @@ int main(int argc, char** argv)
             ((dbname != NULL) ? dbname : ""), errorMessages);
     }
 
-    fout->workingVersionNum = GetVersionNumFromServer(fout);
-
 #ifndef ENABLE_MULTIPLE_NODES
     /*
      * During gs_dump, PQfnumber() is matched according to the lowercase column name.
@@ -842,6 +840,8 @@ int main(int argc, char** argv)
     }
 #endif
 
+    fout->workingVersionNum = GetVersionNumFromServer(fout);
+
     if (CheckIfStandby(fout)) {
         (void)remove(filename);
         exit_horribly(NULL, "%s is not supported on standby or cascade standby\n", progname);