Fix spelling of setDefaultVisibilityCache

No functional change intended.

Change-Id: Icce42de781ddd34ccc2f23e116d7288f967d53d2

gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java

diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
index b5a5d8e..e0a9d76 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
@@ -306,7 +306,7 @@
     setDefaultRenderer(filterConfig);
     setDefaultUrls();
     setDefaultAccess();
-    setDefaultVisbilityCache();
+    setDefaultVisibilityCache();
     setDefaultTimeCache();
     setDefaultBlameCache();
     setDefaultGitwebRedirect();
@@ -380,7 +380,7 @@
     }
   }
 
-  private void setDefaultVisbilityCache() {
+  private void setDefaultVisibilityCache() {
     if (visibilityCache == null) {
       if (config.getSubsections("cache").contains("visibility")) {
         visibilityCache = new VisibilityCache(