remove stolen PID race condition

service/dovecot/run

@@ -15,4 +15,11 @@ adduser -u ${VMAIL_ID} -D -s /bin/false -h ${VMAIL_HOME} ${VMAIL_USER}
 # useradd -u ${VMAIL_ID} -g ${VMAIL_USER} -r -m -d ${VMAIL_HOME} -s /bin/false ${VMAIL_USER}
 chown -Rh vmail:vmail -- ${VMAIL_HOME}
 
+# Stolen PID race condition.
+# In some cases the new process can take the same PID that is in /run/dovecot/master.pid
+# this will make Dovecot think that it is already running, which is not true:
+# ``Fatal: Dovecot is already running with PID 9 (read from /run/dovecot/master.pid)``
+# So remove the leftover before we start the dovecot:
+rm -vf /run/dovecot/master.pid
+
 exec /usr/sbin/dovecot -F