ofURLFileLoader: implementation for https
Update ofURLFileLoader.cpp

unlocks the thread mutex after the requests pool is empty 
Merge branch 'develop' of https://github.com/openframeworks/openFrameworks.git into develop
Update ofURLFileLoader.cpp

moving the lock outside of the while loop. removing the unneeded locks and unlocks.
Merge pull request #1990 from danthemellowman/patch-1

Update ofURLFileLoader.cpp
Merge branch 'develop' of https://github.com/openframeworks/openFrameworks.git into develop