Changes

stp: Fix typo in comment

Change-Id: I9f4a1e5ec0b0d2614b3cec0768e8847fce3e3cdf

testenv: clean: fix cleaning git dir

Don't try to build a PATH that contains the testsuite dir if running the
"clean" action, because then no testsuite is defined.

Fix for:
  $ ./testenv.py clean
  [testenv] + ['rm', '-rf', '/home/user/.cache/osmo-ttcn3-testenv/git']
  Traceback (most recent call last):
    File "/home/user/code/osmo-dev/src/osmo-ttcn3-hacks/./testenv.py", line 137, in <module>
      main()
    File "/home/user/code/osmo-dev/src/osmo-ttcn3-hacks/./testenv.py", line 133, in main
      clean()
    File "/home/user/code/osmo-dev/src/osmo-ttcn3-hacks/./testenv.py", line 117, in clean
      testenv.cmd.run(["rm", "-rf", path])
    File "/home/user/code/osmo-dev/src/osmo-ttcn3-hacks/_testenv/testenv/cmd.py", line 106, in run
      env=generate_env(env),
          ^^^^^^^^^^^^^^^^^
    File "/home/user/code/osmo-dev/src/osmo-ttcn3-hacks/_testenv/testenv/cmd.py", line 72, in generate_env
      path += f":{os.path.join(testenv.testsuite.ttcn3_hacks_dir, testenv.args.testsuite)}"
                                                                  ^^^^^^^^^^^^^^^^^^^^^^
  AttributeError: 'Namespace' object has no attribute 'testsuite'

Change-Id: I65da89581260fc60b3d8da0a93ee04c0c22c7f2c