Update README.rst
Update README.rst

Fix a simple typo
PKRoma/httpie,bitcoinfees/two1-httpie,codingjoe/httpie,codingjoe/httpie,jakubroztocil/httpie,bitcoinfees/two1-httpie,jkbrzt/httpie,jakubroztocil/httpie,jakubroztocil/httpie,PKRoma/httpie,jkbrzt/httpie,jkbrzt/httpie