Runnable identifier: use the actual configuration

A runnable will have its configuration updated by the suite (and job)
configuration at suite creation time.  This configuration should be
used, and not the one at the time the Runnable was crated, to set the
runnable identifier.

Signed-off-by: Cleber Rosa <[email protected]>

avocado/core/nrunner/runnable.py

@@ -113,7 +113,6 @@ def __init__(self, kind, uri, *args, config=None, **kwargs):
         #: expressing assets that the test will require in order to run.
         self.assets = kwargs.pop("assets", None)
         self.kwargs = kwargs
-        self._identifier_format = config.get("runner.identifier_format", "{uri}")
 
     def __repr__(self):
         fmt = (
@@ -157,7 +156,7 @@ def identifier(self):
         Since this is formatter, combined values can be used. Example:
         "{uri}-{args}".
         """
-        fmt = self._identifier_format
+        fmt = self.config.get("runner.identifier_format", "{uri}")
 
         # For the cases where there is no config (when calling the Runnable
         # directly