UI: fix block selection on code for empty line are not highlighted

public/css/gogs.css

@@ -1345,7 +1345,6 @@ footer .ui.language .menu {
 .repository.file.list #file-content .code-view .lines-code ol li,
 .repository.file.list #file-content .code-view .lines-num .hljs li,
 .repository.file.list #file-content .code-view .lines-code .hljs li {
-  padding-left: 5px;
   display: inline-block;
   width: 100%;
 }
@@ -1357,6 +1356,14 @@ footer .ui.language .menu {
 .repository.file.list #file-content .code-view .lines-code .hljs li.active {
   background: #ffffdd;
 }
+.repository.file.list #file-content .code-view .lines-num pre li:before,
+.repository.file.list #file-content .code-view .lines-code pre li:before,
+.repository.file.list #file-content .code-view .lines-num ol li:before,
+.repository.file.list #file-content .code-view .lines-code ol li:before,
+.repository.file.list #file-content .code-view .lines-num .hljs li:before,
+.repository.file.list #file-content .code-view .lines-code .hljs li:before {
+  content: ' ';
+}
 .repository.file.list .sidebar {
   padding-left: 0;
 }

public/less/_repository.less

@@ -277,8 +277,6 @@
 				.lines-num,
 				.lines-code {
 					padding: 0;
-
-
 					pre,
 					ol,
 					.hljs {
@@ -286,12 +284,14 @@
 						margin: 0;
 						padding: 0 !important;
 						li {
-							padding-left: 5px;
 							display: inline-block;
 							width: 100%;
 							&.active {
 								background: #ffffdd;
 							}
+							&:before {
+								content: ' ';
+							}
 						}
 					}
 				}