Resetting url input on new part if datasheet is empty

parts/static/script.js

@@ -182,8 +182,10 @@ function show_part_info(partID) {
 			$('tr#datasheet-head').html($('<td>DATASHEET: <a href="' + data.datasheet + '" target="_blank"><i class="fa fa-file-text" aria-hidden="true"></i></a></td>'));
 			$('input[name=datasheet-url-input]').val(data.datasheet);
 		}
-		else
+		else {
 			$('tr#datasheet-head td').text('DATASHEET: ');
+			$('input[name=datasheet-url-input]').val('');
+		}
 		$('#edit-button').click(function() {
 			init_edit(partID);
 		});