Remove duplicate mimetypes while keeping previous behaviour.

lib/private/mimetypes.list.php

@@ -35,8 +35,6 @@ return array(
 	'c' => 'text/x-c',
 	'c++' => 'text/x-c++src',
 	'doc'=>'application/msword',
-	'doc'=>'application/msword',
-	'docx'=>'application/msword',
 	'docx'=>'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
 	'dv'=>'video/dv',
 	'epub' => 'application/epub+zip',
@@ -84,7 +82,6 @@ return array(
 	'ppt'=>'application/mspowerpoint',
 	'pptx'=>'application/vnd.openxmlformats-officedocument.presentationml.presentation',
 	'psd'=>'application/x-photoshop',
-	'py'=>'application/x-python',
 	'py'=>'text/x-script.python',
 	'reveal' => 'text/reveal',
 	'sgf' => 'application/sgf',
@@ -104,8 +101,6 @@ return array(
 	'wmv'=>'video/x-ms-asf',
 	'xcf'=>'application/x-gimp',
 	'xls'=>'application/msexcel',
-	'xls'=>'application/msexcel',
-	'xlsx'=>'application/msexcel',
 	'xlsx'=>'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
 	'xml'=>'application/xml',
 	'zip'=>'application/zip',