Update connection_http to allow use of pyes from multi-process
Update connection_http to allow use of pyes from multi-process

When I tried to use pyes with an https protected elastic-search with multiprocessing, it fails with very strange errors.
One solution I found is to create one PoolManager per Process.
It seems to works on my desktop, if someone can try the fix.

mavarick/pyes,jayzeng/pyes,aparo/pyes,HackLinux/pyes,aparo/pyes,haiwen/pyes,Fiedzia/pyes,HackLinux/pyes,mavarick/pyes,mavarick/pyes,aparo/pyes,Fiedzia/pyes,jayzeng/pyes,jayzeng/pyes,Fiedzia/pyes,haiwen/pyes,HackLinux/pyes,haiwen/pyes