avocado.core.job: Remove outdated docstring

The `run` does not accept arguments anymore but stores them in `self`.
Let's get rid of the outdated docstring.
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

avocado/core/job.py

@@ -520,15 +520,6 @@ class Job(object):
         """
         Handled main job method. Runs a list of test URLs to its completion.
 
-        Note that the behavior is as follows:
-
-        * If urls is provided alone, just make a simple list with no specific
-          params (all tests use default params).
-        * If urls and multiplex_files are provided, multiplex provides params
-          and variants to all tests it can.
-        * If multiplex_files are provided alone, just use the matrix produced
-          by the file
-
         The test runner figures out which tests need to be run on an empty urls
         list by assuming the first component of the shortname is the test url.