Preventing TimeZone from crashing if the migration cannot run before using it

--HG--
branch : 1.x

src/Orchard/Time/SiteTimeZoneSelector.cs

@@ -13,11 +13,18 @@ namespace Orchard.Time {
         }
 
         public TimeZoneSelectorResult GetTimeZone(HttpContextBase context) {
+            
+            try {
                 var siteTimeZoneId = _workContextAccessor.GetContext(context).CurrentSite.SiteTimeZone;
 
                 if (String.IsNullOrEmpty(siteTimeZoneId)) {
                     return null;
                 }
+            }
+            catch {
+                // if the database could not be updated in time, ignore this provider
+                return null;
+            }
             
             return new TimeZoneSelectorResult {
                 Priority = -5,