fix typos in psr7.rst
fix typos in psr7.rst

Naktibalda/guzzle,Brunty/guzzle,Tobion/guzzle,michabbb-backup/guzzle,jeskew/guzzle,vrkansagara/guzzle,ehough/guzzle,stefanruijsenaars/guzzle,EdgarPE/guzzle,lahmizzar/guzzle,BostjanOb/guzzle,staylor/guzzle,kkopachev/guzzle,stea4lth/guzzle,guzzle/guzzle,grokify/guzzle,wherefortravel/guzzle,BostjanOb/guzzle,mrm/guzzle,jeskew/guzzle,lahmizzar/guzzle,mikicaivosevic/guzzle,michabbb-backup/guzzle,guzzle/guzzle,mikicaivosevic/guzzle,Naktibalda/guzzle,hussainweb/guzzle,ehough/guzzle,thinsoldier/guzzle,mustafavelioglu/guzzle,vrkansagara/guzzle,mustafavelioglu/guzzle,staylor/guzzle,kkopachev/guzzle,mortenhauberg/guzzle,stefanruijsenaars/guzzle,chengky/guzzle,mortenhauberg/guzzle,sulfo/guzzle,thinsoldier/guzzle,mrm/guzzle,paveljanda/guzzle,cenxun/guzzle,grokify/guzzle,EdgarPE/guzzle,Brunty/guzzle,stea4lth/guzzle,sulfo/guzzle,duyhuynhngoc/guzzle,duyhuynhngoc/guzzle,cenxun/guzzle,Tobion/guzzle,dshafik/guzzle,chengky/guzzle,hussainweb/guzzle,paveljanda/guzzle,wherefortravel/guzzle,dshafik/guzzle