Removed trailing white spaces

Removed trailing whitespaces with

```sh
for file in `grep -r " $" * | cut -d : -f 1 | sort | uniq | grep -v " "`; do sed -i 's/[ \t]*$//' $file; done
```

and some handwork.

public/css/gogs.css

@@ -1266,7 +1266,7 @@ body {
 #issue .issue-child .issue-content .user .avatar {
     height: 21px;
     width: 21px;
-} 
+}
 
 #issue .issue-line {
     border-color: #CCC;
@@ -1808,7 +1808,7 @@ body {
     position: absolute;
     top: 0px;
     bottom: 0px;
-    
+
     margin: 5px;
     padding: 8px;