Fix: --setopt and repo with dots

The "--setopt" have had a problem with repositories with dots in id.
Repository id may contain dots but option name can't. ->
So, the last dot is delimiter and not the first one.

Example:
"--setopt=re.po.option=value " was parsed as repo id "re" and option
"po.option". Correct result would be repo id "re.po" and option
"option".

dnf/cli/option_parser.py

@@ -99,7 +99,7 @@ class OptionParser(argparse.ArgumentParser):
                 logger.warning(_("Setopt argument has no value: %s"), values)
                 return
             k, v = vals
-            period = k.find('.')
+            period = k.rfind('.')
             if period != -1:
                 repo = k[:period]
                 k = k[period+1:]