Convert parameters array to string before passing to CURL (#35)

Convert parameters array to url-encoded string before passing to CURL, to avoid the case when parameters is a multi-dimension array

lib/Paymentwall/HttpAction.php

@@ -83,15 +83,15 @@ protected function request($httpVerb = '', $url = '', $params = array(), $custom
 		}
 
 		if (!empty($params)) {
-			curl_setopt($curl, CURLOPT_POSTFIELDS, $params);
+			curl_setopt($curl, CURLOPT_POSTFIELDS, http_build_query($params));
+		}
+
+		// CURL_SSLVERSION_TLSv1_2 is defined in libcurl version 7.34 or later
+		// but unless PHP has been compiled with the correct libcurl headers it
+		// won't be defined in your PHP instance.  PHP > 5.5.19 or > 5.6.3
+		if (! defined('CURL_SSLVERSION_TLSv1_2')) {
+			define('CURL_SSLVERSION_TLSv1_2', 6);
 		}
-
-        // CURL_SSLVERSION_TLSv1_2 is defined in libcurl version 7.34 or later
-        // but unless PHP has been compiled with the correct libcurl headers it
-        // won't be defined in your PHP instance.  PHP > 5.5.19 or > 5.6.3
-        if (! defined('CURL_SSLVERSION_TLSv1_2')) {
-            define('CURL_SSLVERSION_TLSv1_2', 6);
-        }
 
 		curl_setopt($curl, CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1_2);
 		curl_setopt($curl, CURLOPT_CUSTOMREQUEST, $httpVerb);