named crashes when setting nsec3param

This was originally reported as Debian Bug and the bug report was:

Package: bind9 Version: 1:9.11.5.P4+dfsg-5.1

Woke up this morning to the following in syslog. Looks to maybe be a race condition when reloading zones that have changed and setting nsec3params immediately after/during the reload.

Sep  3 05:56:06 odroid-dns named[29241]: zone bluematt.me/IN (unsigned):
loaded serial 2015412479
Sep  3 05:56:06 odroid-dns named[29241]: received control channel
command 'signing -nsec3param 1 0 100 D1D6B923 mattcorallo.com'
Sep  3 05:56:06 odroid-dns named[29241]: ../../../lib/dns/rbtdb.c:1494:
REQUIRE(rbtdb->future_version == ((void *)0)) failed, back trace
Sep  3 05:56:06 odroid-dns named[29241]: #0 0xaaaadda1f958 in ??
Sep  3 05:56:06 odroid-dns named[29241]: #1 0xffffb3437944 in ??
Sep  3 05:56:06 odroid-dns named[29241]: #2 0xffffb3a1368c in ??
Sep  3 05:56:06 odroid-dns named[29241]: #3 0xffffb3ad4bd4 in ??
Sep  3 05:56:06 odroid-dns named[29241]: #4 0xffffb345dca0 in ??
Sep  3 05:56:06 odroid-dns named[29241]: #5 0xffffb335b7e4 in ??
Sep  3 05:56:06 odroid-dns named[29241]: #6 0xffffb2ffbadc in ??
Sep  3 05:56:06 odroid-dns named[29241]: exiting (due to assertion failure)