Use more gender neutral language

src/chat_control.py

@@ -429,7 +429,7 @@ class ChatControl(ChatControlBase):
             else:
                 self._send_file_button.set_tooltip_text(
                     _("You need to know the real JID of the contact to send "
-                    "him or her a file."))
+                    "them a file."))
 
         # Convert to GC
         if gajim.config.get_per('accounts', self.account, 'is_zeroconf'):

src/gui_interface.py

@@ -520,8 +520,8 @@ class Interface:
         list_ = [(contact, account)]
         dialogs.YesNoDialog(
                 _('Contact "%s" removed subscription from you') % contact.jid,
-                _('You will always see him or her as offline.\nDo you want to '
-                        'remove him or her from your contact list?'),
+                _('You will always see them as offline.\nDo you want to '
+                        'remove them from your contact list?'),
                 on_response_yes=(on_yes, list_))
             # FIXME: Per RFC 3921, we can "deny" ack as well, but the GUI does
             # not show deny

src/roster_window.py

@@ -3575,7 +3575,7 @@ class RosterWindow:
             if contact.sub == 'to':
                 dialogs.ConfirmationDialog(pritext, sectext + \
                     _('By removing this contact you also remove authorization '
-                    'resulting in him or her always seeing you as offline.'),
+                    'resulting in them always seeing you as offline.'),
                     on_response_ok=(on_ok2, list_))
             elif _('Not in Roster') in contact.get_shown_groups():
                 # Contact is not in roster
@@ -3585,7 +3585,7 @@ class RosterWindow:
             else:
                 dialogs.ConfirmationDialogCheck(pritext, sectext + \
                     _('By removing this contact you also by default remove '
-                    'authorization resulting in him or her always seeing you as'
+                    'authorization resulting in them always seeing you as'
                     ' offline.'),
                     _('I want this contact to know my status after removal'),
                     on_response_ok=(on_ok, list_))