QA - mb_http_input - function returns FALSE for type 'L' or 'l'

Closes GH-9018.

ext/mbstring/tests/mb_http_input_001.phpt

@@ -0,0 +1,17 @@
+--TEST--
+mb_http_input() - Returns FALSE for $type 'L' or 'l'
+--EXTENSIONS--
+mbstring
+--INI--
+input_encoding=-1
+--FILE--
+<?php
+var_dump(mb_http_input('L'));
+var_dump(mb_http_input('l'));
+?>
+--EXPECT--
+Warning: PHP Startup: INI setting contains invalid encoding "-1" in Unknown on line 0
+
+Warning: PHP Startup: INI setting contains invalid encoding "-1" in Unknown on line 0
+bool(false)
+bool(false)