Merge pull request #192 from CESNET/fix-type-error-rpc-connector

fix: prevent type errors in RPC connector

Author: vyskocilpavel

lib/RpcConnector.php

@@ -75,6 +75,13 @@ public function get($manager, $method, $params = [])
         Logger::debug('perun.RPC: GET call ' . $uri . ' with params: ' . $paramsQuery . ', response : ' .
             $json . ' in: ' . $responseTime . 's.');
 
+        if ($json === false) {
+            throw new Exception(
+                'Cant\'t get response from Perun. Call: ' . $uri . ', Params: ' . $paramsQuery .
+                ', Response: ' . $json
+            );
+        }
+
         $result = json_decode($json, true);
 
         if (json_last_error() !== JSON_ERROR_NONE) {
@@ -121,6 +128,13 @@ public function post($manager, $method, $params = [])
         Logger::debug('perun.RPC: POST call ' . $uri . ' with params: ' . $paramsJson . ', response : ' .
             $json . ' in: ' . $responseTime . 's.');
 
+        if ($json === false) {
+            throw new Exception(
+                'Can\'t get response from Perun. Call: ' . $uri . ', Params: ' . $paramsQuery .
+                ', Response: ' . $json
+            );
+        }
+
         $result = json_decode($json, true);
 
         if (json_last_error() !== JSON_ERROR_NONE) {