librepo: Fix the key string parsing in url_substitution

[jaankit]

• Break the loop if last char of key string is '_'
• Use Case: Lets say: releasever = 1.0 basearch = x8664 URL String: $releasever$basearch
  • Without fix:
    • parsed as $releasever_x86_64
  • With fix:
    • parsed as 1.0_x86_64

= changelog = msg: Fix the key string parsing in url_substitution type: bugfix resolves: string parsing issue in url_substitution

Signed-off-by: Ankit Jain ankitja@vmware.com

[Conan-Kudo]

@jaankit Thanks for the fix!