fix performance of update removal

services/track-changes/app/coffee/RedisManager.coffee

@@ -21,7 +21,7 @@ module.exports = RedisManager =
 		multi = rclient.multi()
 		# Delete all the updates which have been applied (exact match)
 		for update in docUpdates or []
-			multi.lrem Keys.uncompressedHistoryOps({doc_id}), 0, update
+			multi.lrem Keys.uncompressedHistoryOps({doc_id}), 1, update
 		multi.exec (error, results) ->
 			return callback(error) if error?
 			# It's ok to delete the doc_id from the set here. Even though the list

services/track-changes/test/unit/coffee/RedisManager/RedisManagerTests.coffee

@@ -56,12 +56,12 @@ describe "RedisManager", ->
 
 			it "should delete the first update from redis", ->
 				@rclient.lrem
-					.calledWith("UncompressedHistoryOps:#{@doc_id}", 0, @jsonUpdates[0])
+					.calledWith("UncompressedHistoryOps:#{@doc_id}", 1, @jsonUpdates[0])
 					.should.equal true
 
 			it "should delete the second update from redis", ->
 				@rclient.lrem
-					.calledWith("UncompressedHistoryOps:#{@doc_id}", 0, @jsonUpdates[1])
+					.calledWith("UncompressedHistoryOps:#{@doc_id}", 1, @jsonUpdates[1])
 					.should.equal true
 
 			it "should delete the doc from the set of docs with history ops", ->