Merge pull request zendframework/zendframework#4820. Fix zendframewor…

…k/zendframework#4819 in master

src/Decode.php

@@ -115,7 +115,7 @@ public static function splitMessage($message, &$headers, &$body, $EOL = Mime::LI
 
         // see @ZF2-372, pops the first line off a message if it doesn't contain a header
         if (!$strict) {
-            $parts = explode(': ', $firstline, 2);
+            $parts = explode(':', $firstline, 2);
             if (count($parts) != 2) {
                 $message = substr($message, strpos($message, $EOL)+1);
             }