fixed:php 8.0兼容

`SendRequestTrait::createCommonSignedUrl(array $args=[],$signature)`在php8.0中会导致以下错误`Required parameter $signature follows optional parameter $args`

Obs/Internal/SendRequestTrait.php

@@ -68,14 +68,14 @@ public function createSignedUrl(array $args=[]){
 	    if (strcasecmp($this -> signature, 'v4') === 0) {
 	        return $this -> createV4SignedUrl($args);
 	    }
-	    return $this->createCommonSignedUrl($args, $this->signature);
+	    return $this->createCommonSignedUrl($this->signature,$args);
 	}
 
 	public function createV2SignedUrl(array $args=[]) {
-	    return $this->createCommonSignedUrl($args, 'v2');
+	    return $this->createCommonSignedUrl( 'v2',$args);
 	}
 
-	private function createCommonSignedUrl(array $args=[], $signature) {
+	private function createCommonSignedUrl(string $signature,array $args=[]) {
 	    if(!isset($args['Method'])){
 	        $obsException = new ObsException('Method param must be specified, allowed values: GET | PUT | HEAD | POST | DELETE | OPTIONS');
 	        $obsException-> setExceptionType('client');
@@ -715,4 +715,4 @@ function (RequestException $exception) use ($model, $operation, $params, $callba
 				}
 		);
 	}
-}
+}