[FIX] environment.sample : remove space that make build failing

[legalsylvain]

Trivial fix.

Step to reproduce :

• install the oca-github-bot
• create an environment file based on the environment.sample file.
• run docker-compose up --build

Result

ERROR: In file /home/user/grap_dev/grap-ocabot-env/src/oca-github-bot/environment: environment variable name '('https://pypi.org/simple', 'https://upload.pypi.org/legacy/', 'pypiuser', 'pypipassword'),' may not contain whitespace.