Revert "Continued attempt to fix https://github.com/couchbaselabs/TouchDB-iOS/issues/266: TDHTTPResponse -cleanUp should rstop the router from observing notifications. Q: is this a good way to fix - should cleanUp instead set _router to nil or call its -stopNow which does the same, also in a synchronized way?"

This reverts commit db4147e0b2d07e78e63d596e6d736646883f8e8b.
Revert "Fixed the crashing bug https://github.com/couchbaselabs/TouchDB-iOS/issues/266"

This reverts commit 349b47da3f70d2c89f56a4ff6a8377f067421e8e.