Avoid calling repo_name from load_nameverrel
Method load_repo_name() calls load_nameverrel(), which calls
repo_name() to format its error message. That leads to calling
load_repo_name() again, and so on to endless recursion. Prevent this
situation by simplifying load_nameverrel() error messages.
Fixes: #657
JIRA: RHELCMP-11192
Merges: https://pagure.io/rpkg/pull-request/658
Signed-off-by: Otto Liljalaakso <otto.liljalaakso@iki.fi>