Fetch emails right at startup instead of waiting for 10 minutes.

Especially when first setting up the configuration for consuming
documents from emails it makes sense to quickly test the changes. Having
to wait for 10 minutes is not acceptable.

There are two ways around it that come to my mind: the simple approach
is to always fetch the emails when Paperless first starts. This way the
fetching of emails can be tested straight away.
The alternative would be to have a configuration option that allows to
set the interval in which emails are checked. The user could then reduce
it to test the setup and increase it again later on. This seems
needlessly complicated though, so fetching at startup it is.

src/documents/management/commands/document_consumer.py

@@ -28,6 +28,7 @@ class Command(BaseCommand):
 
         self.file_consumer = None
         self.mail_fetcher = None
+        self.first_iteration = True
 
         BaseCommand.__init__(self, *args, **kwargs)
 
@@ -66,6 +67,9 @@ class Command(BaseCommand):
         self.file_consumer.consume()
 
         # Occasionally fetch mail and store it to be consumed on the next loop
+        # We fetch email when we first start up so that it is not necessary to
+        # wait for 10 minutes after making changes to the config file.
         delta = self.mail_fetcher.last_checked + self.MAIL_DELTA
-        if delta < datetime.datetime.now():
+        if self.first_iteration or delta < datetime.datetime.now():
+            self.first_iteration = False
             self.mail_fetcher.pull()