Close ctx mutex on last socket termination
Close ctx mutex on last socket termination

Signed-off-by: Martin Sustrik <4dd6061be1198639e8b05ce4fd5ead7a0dcaa0f4@250bpm.com>

ttyangf/nanomsg,JackDunaway/featherweight-nanomsg,smithed/nanomsg,gdamore/mamomsg,pch957/nanomsg,thisco-de/nanomsg,reqshark/nanomsg,JackDunaway/featherweight-nanomsg,smithed/nanomsg,cosin2008/nanomsg.NET,krafczyk/nanomsg,smithed/nanomsg,wirebirdlabs/featherweight-nanomsg,pch957/nanomsg,nirs/nanomsg,TTimo/nanomsg,tempbottle/nanomsg,cosin2008/nanomsg.NET,reqshark/nanomsg,hyperfact/nanomsg,featherweight/ftw-kernel-nanomsg,krafczyk/nanomsg,simplestbest/nanomsg,wirebirdlabs/featherweight-nanomsg,reqshark/nanomsg,zerotacg/nanomsg,TTimo/nanomsg,wfxiang08/nanomsg,hyperfact/nanomsg,modulexcite/nanomsg,modulexcite/nanomsg,linearregression/nanomsg,tempbottle/nanomsg,pch957/nanomsg,nirs/nanomsg,pakozm/nanomsg,gdamore/mamomsg,snikulov/nanomsg,simplestbest/nanomsg,tempbottle/nanomsg,pakozm/nanomsg,thisco-de/nanomsg,potatogim/nanomsg,imp/nanomsg,gdamore/mamomsg,yan97ao/nanomsg,modulexcite/nanomsg,ttyangf/nanomsg,ttyangf/nanomsg,imp/nanomsg,wfxiang08/nanomsg,simplestbest/nanomsg,wfxiang08/nanomsg,linearregression/nanomsg,krafczyk/nanomsg,TTimo/nanomsg,wirebirdlabs/featherweight-nanomsg,nirs/nanomsg,yan97ao/nanomsg,featherweight/ftw-kernel-nanomsg,imp/nanomsg,linearregression/nanomsg,zerotacg/nanomsg,yan97ao/nanomsg,snikulov/nanomsg,pakozm/nanomsg,zerotacg/nanomsg,JackDunaway/featherweight-nanomsg,TTimo/nanomsg,smithed/nanomsg,ttyangf/nanomsg,hyperfact/nanomsg,potatogim/nanomsg,potatogim/nanomsg,cosin2008/nanomsg.NET