Fix axelrc parsing for interfaces list values

[codecrypt112]

Summary

• preserve the full config value after = instead of truncating at first whitespace
• trim only trailing whitespace from config values
• this allows interfaces = ip1 ip2 ip3 to be parsed as an actual list

Why

Issue #401 reports that interfaces appears to do nothing. The parser currently truncates values at the first space, so only the first token survives.

Closes #401