Box-sizing does not need vendor prefix anymore

http://caniuse.com/#search=box-sizing

Signed-off-by: Morris Jobke <hey@morrisjobke.de>

apps/files/css/upload.scss

@@ -1,6 +1,4 @@
 #upload {
-	-moz-box-sizing: border-box;
-	-webkit-box-sizing: border-box;
 	box-sizing: border-box;
 	height: 36px;
 	width: 39px;
@@ -26,8 +24,6 @@
 .file_upload_form { display:inline; float:left; margin:0; padding:0; cursor:pointer; overflow:visible; }
 
 #uploadprogresswrapper, #uploadprogresswrapper * {
-	-moz-box-sizing: border-box;
-	-webkit-box-sizing: border-box;
 	box-sizing: border-box;
 }
 

core/css/jquery.ocdialog.scss

@@ -6,8 +6,6 @@
 	padding: 15px;
 	z-index: 10000;
 	font-size: 100%;
-	-webkit-box-sizing: border-box;
-	-moz-box-sizing: border-box;
 	box-sizing: border-box;
 	min-width: 200px;
 	top: 50%;

settings/css/settings.scss

@@ -1146,8 +1146,6 @@ table.grid td.date {
 }
 
 #selectGroups select {
-	-moz-box-sizing: border-box;
-	-webkit-box-sizing: border-box;
 	box-sizing: border-box;
 	display: inline-block;
 	height: 36px;