pungi: Only add logger once

The Pungi object reuses the same logger for all its instances. Every
time a new instance is created, a stream handler would be added. This
means that a second instance will print everything twice. When running
tests, tens of instances would be created.

This patch only adds the handler if there are no handlers configured
yet.

Signed-off-by: Lubomír Sedlář <lsedlar@redhat.com>

pungi/gather.py

@@ -214,6 +214,7 @@ class Pungi(PungiBase):
         lock = lockfile.LockFile(filename)
         self.yumlock = ReentrantYumLock(lock, self.logger)
 
+        if not self.logger.handlers:
             # Create the stdout/err streams and only send INFO+ stuff there
             formatter = logging.Formatter('%(name)s:%(levelname)s: %(message)s')
             console = logging.StreamHandler()