little fixes

src/base58.php

@@ -306,7 +306,7 @@ class base58
     for ($i = count($data) - 1; $i >= 0; $i--) {
       $digit = strpos(self::$alphabet, chr($data[$i]));
       if ($digit < 0) {
-        throw new Exception("base58->decode_block(): Invalid character ($digit \"{$digit}\" not found in base58::$alphabet)");
+        throw new Exception("base58->decode_block(): Invalid character ($digit \"{$digit}\" not found in base58::\$alphabet)");
       }
 
       $product = bcadd(bcmul($order, $digit), $res_num);

src/jsonRPCClient.php

@@ -97,8 +97,7 @@ class jsonRPCClient
             }
             $this->validate( !is_null($responseDecoded['error']), $errorMessage);
         }
-        if(isset($responseDecoded['result']) return $responseDecoded['result'];
-        else return -1;
+        return $responseDecoded['result'] ?? -1;
     }
 
     protected function & getResponse(&$pRequest, &$path)