using abspath for resolving template path

[M-Igashi]

os.path.realpath tries to resolve symlink between template and actual working directory which causes 404 error in multi market config and/or docker images. os.path.abspath is good enough to resolve the path.

Description

TESTING STAGE

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] I have read CONTRIBUTING.md
• [x] I fully understand Github Flow.
• [x] My code adheres to the code style of this project.
• [ ] I have updated the documentation in /docs if I have changed the config, arguments, logic in how the bot works, or anything that understandably needs a documentation change.
• [ ] I have updated the config file accordingly if my change requires a new configuration setting or changes an existing one.
• [ ] I have tested the bot with no issues for 24 continuous hours. If issues were experienced, they have been patched and tested again.

[rnevet]

lgtm, was the issue related to using symlinks?

original security issue was related to using /../../ to reach parent directory of webserver and access config file and maybe other location on file system.

@utdrmac does this solve the issue for you as well?

[M-Igashi]

not exactly the matter of symlink, but realpath method strains the path target into single after resolving the absolute path which is the core function of abspath.