Do not use sal/log.hxx in extensions

"For now, this functionality should only be used internally within LibreOffice.
It may change again in a future version." (sal/log.hxx)

And the condition that was checked already causes a RuntimeException, so was
somewhat redundant anyway.  Thanks to mstahl for spotting this.

Change-Id: I51cc4e75b3d3ffc97943613c61cb93c1fb48e59b

mysqlc/source/mysqlc_driver.cxx

@@ -217,7 +217,6 @@ Reference< XConnection > SAL_CALL MysqlCDriver::connect(const OUString& url, con
     if ( !cppDriver )
     {
         impl_initCppConn_lck_throw();
-        SAL_WARN_IF( !cppDriver, "mysqlc", "MySQLCDriver::connect: internal error." );
         if ( !cppDriver )
             throw RuntimeException("MySQLCDriver::connect: internal error.", *this );
     }