don't complain about raw headers that are not name: value

For example, HTTP/1.1 401 Unauthorized

app/code/community/EcomDev/PHPUnit/Controller/Response/Http.php

@@ -91,6 +91,7 @@ class EcomDev_PHPUnit_Controller_Response_Http
         $this->_sentHeaders[null] = 'HTTP/1.1 ' . $this->_httpResponseCode;
 
         foreach ($this->_headersRaw as $headerRaw) {
+            if (strpos($headerRaw, ':') === false) { continue; }
             list($headerName, $headerValue) = explode(':', $headerRaw, 2);
             $headerName = $this->_normalizeHeader($headerName);
             if (isset($this->_sentHeaders[$headerName])) {
@@ -224,4 +225,4 @@ class EcomDev_PHPUnit_Controller_Response_Http
 
         return $this->_sentHeaders === null;
     }
-}
\ No newline at end of file
+}