aggressive-indent-mode slows down when using multiple cider connections

[BrunoBonacci]

It appears that when running 3-4 repl connections at the same time aggressive-indent-mode indent mode starts to slow down at the point that typing is impacted with a couple of seconds of delay.

Env:

• GNU Emacs 25.1.1 (x86_64-apple-darwin13.4.0, NS appkit-1265.21 Version 10.9.5 (Build 13F1911)) of 2016-09-21
• OS X El Capitan
• cider - 20170103
• aggressive-indent - 20161201