fix scripts/mysql.sql from gogs to gitea (#1161)

scripts/mysql.sql

@@ -1,2 +1,2 @@
-DROP DATABASE IF EXISTS gogs;
-CREATE DATABASE IF NOT EXISTS gogs CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;
+DROP DATABASE IF EXISTS gitea;
+CREATE DATABASE IF NOT EXISTS gitea CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;