Fix Spelling mistakes in setPDO method on RPDO.php. Closes #875.

Author: gabordemooij

RedBeanPHP/Driver/RPDO.php

@@ -510,7 +510,7 @@ public function setPDO( \PDO $pdo, $options = array() ) {
 		if ( isset($options['runInitCode']) )   $runInitCode   = $options['runInitCode'];
 		if ( isset($options['stringFetch']) )   $stringFetch   = $options['stringFetch'];
 
-		if ($connected) $this->connected = $connected;
+		if ($connected) $this->isConnected = $connected;
 		if ($setEncoding) $this->setEncoding();
 		if ($setAttributes) {
 			$this->pdo->setAttribute( \PDO::ATTR_ERRMODE,\PDO::ERRMODE_EXCEPTION );