mysqlc: -Werror=unused-function

Change-Id: I8b1f4b7c78a10ce604a63aff47d2df2d1d10dc26
Reviewed-on: https://gerrit.libreoffice.org/19800Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Stahl <mstahl@redhat.com>

mysqlc/source/mysqlc_driver.cxx

@@ -110,7 +110,9 @@ Sequence< rtl::OUString > SAL_CALL MysqlCDriver::getSupportedServiceNames()
     return getSupportedServiceNames_Static();
 }
 
+#ifndef SYSTEM_MYSQL_CPPCONN
 extern "C" { static void SAL_CALL thisModule() {} }
+#endif
 
 void MysqlCDriver::impl_initCppConn_lck_throw()
 {