Supress make warning present on Benthos forks

[mkysel]

If you develop Benthos on a fork, you won't have any git tags present by default.

The git describe throws an annoying error which shows for any make command

$ git describe --tags
fatal: No names found, cannot describe anything.

such as:

$ make
fatal: No names found, cannot describe anything.
make: Nothing to be done for `all'.

Supressing the error message makes the make output way more pleasant