Use {lb} and {rb} instead of {literal}

These do not turn off HTML escaping so they are less error prone.

No functional change intended.

Change-Id: I5b9a149d531c58efa5f8ce59241d96bcc718bcb9
diff --git a/gitiles-servlet/src/main/resources/com/google/gitiles/templates/RepositoryIndex.soy b/gitiles-servlet/src/main/resources/com/google/gitiles/templates/RepositoryIndex.soy
index b4e7062..ec6e67e 100644
--- a/gitiles-servlet/src/main/resources/com/google/gitiles/templates/RepositoryIndex.soy
+++ b/gitiles-servlet/src/main/resources/com/google/gitiles/templates/RepositoryIndex.soy
@@ -65,7 +65,7 @@
 <div class="CloneRepo">
   <div class="CloneRepo-title">Clone this repo:</div>
   <input type="text" class="u-monospace CloneRepo-command"
-         onclick="{literal}this.focus();if(this.selectionStart==this.selectionEnd){this.select()}{/literal}"
+         onclick="this.focus();if(this.selectionStart==this.selectionEnd){lb}this.select(){rb}"
          readonly="readonly" value="git clone {$cloneUrl}">
 </div>