Add note explaining redundant try/catch

Author: myieye

src/SIL.Harmony/Db/CrdtRepository.cs

@@ -332,6 +332,8 @@ public async Task AddSnapshots(IEnumerable<ObjectSnapshot> snapshots)
             }
         }
 
+        // this extra try/catch was added as a quick way to get the NewEntityOnExistingEntityIsNoOp test to pass
+        // it will be removed again in a larger refactor in https://github.com/sillsdev/harmony/pull/56
         try
         {
             await _dbContext.SaveChangesAsync();