Fixes a race condition when using `watchable_map_keyed_var_t`
Fixes a race condition when using `watchable_map_keyed_var_t`

eliangidoni/rethinkdb,bchavez/rethinkdb,bpradipt/rethinkdb,jmptrader/rethinkdb,mbroadst/rethinkdb,robertjpayne/rethinkdb,grandquista/rethinkdb,robertjpayne/rethinkdb,mbroadst/rethinkdb,bpradipt/rethinkdb,grandquista/rethinkdb,bchavez/rethinkdb,bchavez/rethinkdb,robertjpayne/rethinkdb,Qinusty/rethinkdb,jmptrader/rethinkdb,JackieXie168/rethinkdb,mbroadst/rethinkdb,bchavez/rethinkdb,robertjpayne/rethinkdb,niieani/rethinkdb,bchavez/rethinkdb,eliangidoni/rethinkdb,dparnell/rethinkdb,niieani/rethinkdb,dparnell/rethinkdb,niieani/rethinkdb,JackieXie168/rethinkdb,niieani/rethinkdb,jmptrader/rethinkdb,bchavez/rethinkdb,catroot/rethinkdb,bpradipt/rethinkdb,niieani/rethinkdb,catroot/rethinkdb,eliangidoni/rethinkdb,grandquista/rethinkdb,dparnell/rethinkdb,mbroadst/rethinkdb,dparnell/rethinkdb,catroot/rethinkdb,robertjpayne/rethinkdb,JackieXie168/rethinkdb,JackieXie168/rethinkdb,eliangidoni/rethinkdb,Qinusty/rethinkdb,jmptrader/rethinkdb,bpradipt/rethinkdb,jmptrader/rethinkdb,mbroadst/rethinkdb,grandquista/rethinkdb,Qinusty/rethinkdb,eliangidoni/rethinkdb,eliangidoni/rethinkdb,JackieXie168/rethinkdb,robertjpayne/rethinkdb,dparnell/rethinkdb,catroot/rethinkdb,Qinusty/rethinkdb,Qinusty/rethinkdb,bpradipt/rethinkdb,eliangidoni/rethinkdb,Qinusty/rethinkdb,dparnell/rethinkdb,JackieXie168/rethinkdb,grandquista/rethinkdb,robertjpayne/rethinkdb,robertjpayne/rethinkdb,Qinusty/rethinkdb,mbroadst/rethinkdb,bpradipt/rethinkdb,mbroadst/rethinkdb,eliangidoni/rethinkdb,bchavez/rethinkdb,mbroadst/rethinkdb,bchavez/rethinkdb,grandquista/rethinkdb,Qinusty/rethinkdb,bchavez/rethinkdb,grandquista/rethinkdb,niieani/rethinkdb,robertjpayne/rethinkdb,JackieXie168/rethinkdb,dparnell/rethinkdb,bpradipt/rethinkdb,dparnell/rethinkdb,catroot/rethinkdb,dparnell/rethinkdb,grandquista/rethinkdb,JackieXie168/rethinkdb,grandquista/rethinkdb,Qinusty/rethinkdb,eliangidoni/rethinkdb,catroot/rethinkdb,catroot/rethinkdb,jmptrader/rethinkdb,catroot/rethinkdb,jmptrader/rethinkdb,bpradipt/rethinkdb,niieani/rethinkdb,niieani/rethinkdb,mbroadst/rethinkdb,JackieXie168/rethinkdb,jmptrader/rethinkdb,bpradipt/rethinkdb