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.

templates/install.tmpl

@@ -87,7 +87,7 @@
                 <p class="help-block">The user has access to visit and run Gogs.</p>
             </div>
         </div>
-        
+
         <div class="form-group">
             <label class="col-md-3 control-label">Domain: </label>
             <div class="col-md-8">
@@ -95,7 +95,7 @@
                 <p class="help-block">This affects SSH clone URL.</p>
             </div>
         </div>
-        
+
         <div class="form-group">
             <label class="col-md-3 control-label">App URL: </label>
             <div class="col-md-8">