Fix literal-comparison pylint errors

gajim/common/connection.py

@@ -732,7 +732,7 @@ class Connection(CommonConnection, ConnectionHandlers):
                         return
                     is_form = data[2]
                     conf = data[1]
-                    if data[4] is not '':
+                    if data[4] != '':
                         helpers.replace_dataform_media(conf, data[4])
                     if self.new_account_form:
                         def _on_register_result(result):

gajim/plugins/pluginmanager.py

@@ -629,7 +629,7 @@ class PluginManager(metaclass=Singleton):
                         os.path.dirname(file_path))
 
                     for option in fields:
-                        if conf.get('info', option) is '':
+                        if conf.get('info', option) == '':
                             raise configparser.NoOptionError(option, 'info')
                         if option == 'description':
                             setattr(module_attr, option, _(conf.get('info', option)))

gajim/remote_control.py

@@ -90,7 +90,7 @@ class Server:
 
         args = list(parameters.unpack())
         for i, sig in enumerate(self.method_inargs[method_name]):
-            if sig is 'h':
+            if sig == 'h':
                 msg = invocation.get_message()
                 fd_list = msg.get_unix_fd_list()
                 args[i] = fd_list.get(args[i])