Remove default value from description

Resolves #1693

Author: patiencedaur

doc/book/replication/repl_monitoring.rst

@@ -55,7 +55,8 @@ The primary indicators of replication health are:
 *   :ref:`idle <box_info_replication_upstream_idle>`, the time (in seconds) since
     the instance received the last event from a master.
 
-    A master sends heartbeat messages to a replica every second, and the master
+    If the master has no updates to send to the replicas, it sends heartbeat messages
+    every ``replication_timeout`` seconds. The master
     is programmed to disconnect if it does not see acknowledgments of the heartbeat messages
     within :ref:`replication_timeout <cfg_replication-replication_timeout>` * 4
     seconds.

locale/ru/LC_MESSAGES/book/replication/repl_monitoring.po

@@ -100,13 +100,15 @@ msgstr ""
 "с момента получения последнего события от мастера."
 
 msgid ""
-"A master sends heartbeat messages to a replica every second, and the master "
+"If the master has no updates to send to the replicas, it sends heartbeat messages "
+"every ``replication_timeout`` seconds. The master "
 "is programmed to disconnect if it does not see acknowledgments of the "
 "heartbeat messages within :ref:`replication_timeout <cfg_replication-"
 "replication_timeout>` * 4 seconds."
 msgstr ""
-"Мастер отправляет сообщения контрольного сигнала на реплику каждую секунду, "
-"и мастер запрограммирован на отключение, если он не получает сообщения "
+"Если на мастере нет новых данных, требующих репликации, он отправляет на реплики "
+"сообщения контрольного сигнала каждые ``replication_timeout`` секунд. "
+"Мастер запрограммирован на отключение, если он не получает сообщения "
 "контрольного сигнала дольше :ref:`replication_timeout <cfg_replication-"
 "replication_timeout>` * 4 секунд."