!3682 修复带dolphin插件时，从3.1.0升级/回滚到5.x失败的问题

Merge pull request !3682 from pengjiong/fix_col

src/include/catalog/upgrade_sql/rollback_catalog_maindb/rollback-post_catalog_maindb_92_830.sql

@@ -1 +1,8 @@
-drop extension if exists dolphin;
+DO $$
+BEGIN
+    -- 92780 is openGauss 3.1.0, which has dolphin, so should not drop it.
+    if working_version_num() < 92780 then
+        drop extension if exists dolphin;
+    end if;
+END
+$$;

src/include/catalog/upgrade_sql/rollback_catalog_otherdb/rollback-post_catalog_otherdb_92_830.sql

@@ -1 +1,8 @@
-drop extension if exists dolphin;
+DO $$
+BEGIN
+    -- 92780 is openGauss 3.1.0, which has dolphin, so should not drop it.
+    if working_version_num() < 92780 then
+        drop extension if exists dolphin;
+    end if;
+END
+$$;