icons: Clean up upload.svg

Remove metadata and clean up the SVG tags to make it simpler.

src/default-theme/icons/md/upload.svg

@@ -1,10 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!-- Generator: Adobe Illustrator 19.2.1, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
-<svg version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
-	 viewBox="0 0 18 18" style="enable-background:new 0 0 18 18;" xml:space="preserve">
-<style type="text/css">
-	.st0{fill:none;}
-</style>
-<path class="st0" d="M0,0h18v18H0V0z"/>
-<path d="M6.8,11.8h4.5V7.2h3L9,2L3.8,7.2h3V11.8z M3.8,14h10.5v2H3.8V14z"/>
+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 18 18">
+    <path fill="none" d="M0,0h18v18H0V0z"/>
+    <path d="M6.8,11.8h4.5V7.2h3L9,2L3.8,7.2h3V11.8z M3.8,14h10.5v2H3.8V14z"/>
 </svg>