NOBUG: Fixed SVG browser compatibility

mod/forum/pix/i/pinned.svg

@@ -2,7 +2,7 @@
 <!-- Generator: Adobe Illustrator 18.0.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
 <!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
 <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="-0.8 0 16 16" enable-background="new -0.8 0 16 16" xml:space="preserve" width="16px" height="16px">
+	 viewBox="-0.8 0 16 16" enable-background="new -0.8 0 16 16" xml:space="preserve" width="16px" height="16px" preserveAspectRatio="xMinYMid meet">
 <path fill="#999999" d="M6.3,7.1V2.8c0-0.1,0-0.2-0.1-0.2C6.2,2.5,6.1,2.5,6,2.5c-0.1,0-0.2,0-0.2,0.1C5.7,2.6,5.7,2.7,5.7,2.8v4.3
 	c0,0.1,0,0.2,0.1,0.2S5.9,7.4,6,7.4c0.1,0,0.2,0,0.2-0.1S6.3,7.2,6.3,7.1L6.3,7.1z M12.8,10.5c0,0.2-0.1,0.3-0.2,0.4
 	c-0.1,0.1-0.3,0.2-0.4,0.2H8l-0.5,4.6c0,0.1,0,0.1-0.1,0.2C7.4,16,7.3,16,7.2,16h0c-0.2,0-0.3-0.1-0.3-0.3l-0.7-4.7H2.3