python: remove :returns: keywords from functions returning nothing

Signed-off-by: Justus Winter <4winter@informatik.uni-hamburg.de>

bindings/python/notmuch/database.py

@@ -176,7 +176,6 @@ class Database(object):
 
         :param path: A directory in which we should create the database.
         :type path: str
-        :returns: Nothing
         :raises: :exc:`NotmuchError` in case of any failure
                     (possibly after printing an error message on stderr).
         """
@@ -200,7 +199,6 @@ class Database(object):
 
         :param status: Open the database in read-only or read-write mode
         :type status:  :attr:`MODE`
-        :returns: Nothing
         :raises: Raises :exc:`NotmuchError` in case of any failure
                     (possibly after printing an error message on stderr).
         """
@@ -699,7 +697,6 @@ class Directory(object):
         Retrieves a previously stored mtime for this directory.
 
         :param mtime: A (time_t) timestamp
-        :returns: Nothing on success, raising an exception on failure.
         :raises: :exc:`NotmuchError`:
 
                         :attr:`STATUS`.NOT_INITIALIZED

bindings/python/notmuch/message.py

@@ -513,7 +513,6 @@ class Message(Python3StringMixIn):
                      *Message.FLAG.MATCH*
         :param value: A bool indicating whether to set or unset the flag.
 
-        :returns: Nothing
         :raises: :exc:`NotInitializedError` if the message
               is not initialized.
         """

bindings/python/notmuch/query.py

@@ -88,7 +88,6 @@ class Query(object):
         :type db: :class:`Database`
         :param querystr: The query string
         :type querystr: utf-8 encoded str or unicode
-        :returns: Nothing
         :raises:
             :exc:`NullPointerError` if the query creation failed
                 (e.g. too little memory).