Template substitution is too loose

[arnaud]

Description

The template substitution script replaces template blocks in a too loose way.

Steps to Reproduce

1. Use multiple if-env blocks in etc/nginx/conf.d/a7.conf
2. Make sure to put some custom nginx configuration between these blocks
3. Start the service by setting the corresponding env var to false
4. Which will disable these blocks
5. And also whatever was in the between (from step 2)

Reproduces how often:

Always

Versions

1.6.0

Additional Information

In the meantime, make sure not to use multiple template blocks for the same env var in etc/nginx/conf.d/a7.conf.