Looks like it stores the over long abbreviation.
So should probably patch:
--- tz/releases/tzdata2017a/africa 2017-02-23 00:37:19.000000000 -0700
+++ tz/releases/tzdata2017b/africa 2017-03-01 14:36:43.479882200 -0700
@@ -431,7 +431,7 @@ Link Africa/Nairobi Indian/Mayotte
# Zone NAME GMTOFF RULES FORMAT [UNTIL]
Zone Africa/Monrovia -0:43:08 - LMT 1882
-0:43:08 - MMT 1919 Mar # Monrovia Mean Time
- -0:44:30 - -004430 1972 May
+ -0:44:30 - -0044 1972 May
0:00 - GMT