Make sure commentVisibilityStrategy is reset on resetting prefs

Change-Id: Ieca953973334a23674353bf7da323043a5e3e6d2
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountGeneralPreferences.java

diff --git a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountGeneralPreferences.java b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountGeneralPreferences.java
index 53ca908..7244f49 100644
--- a/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountGeneralPreferences.java
+++ b/gerrit-reviewdb/src/main/java/com/google/gerrit/reviewdb/client/AccountGeneralPreferences.java
@@ -290,6 +290,7 @@
     dateFormat = null;
     timeFormat = null;
     relativeDateInChangeTable = false;
+    commentVisibilityStrategy = null;
     diffView = null;
   }
 }