make has_plugin detection method more reliable (#362)

* fix has_plugin detection method
* use even better method :)
* add changelog fragment
* fix forgotten file extension
* Double Backticks ;)
* Add PR link to changelog
Co-authored-by: Mike Graves <mgraves@redhat.com>

plugins/modules/helm.py

@@ -418,7 +418,7 @@ def has_plugin(command, plugin):
     for line in out.splitlines():
         if line.startswith("NAME"):
             continue
-        name, _rest = line.split("\t", 1)
+        name, _rest = line.split(None, 1)
         if name == plugin:
             return True
     return False