[PATCH] Fix broken 'svnadmin create --pre-1.x-compatible'

Hi,

I've noticed that running 'svnadmin create --pre-1.4-compatible REPOS_NAME'
around trunk_at_r1546963 incorrectly errors out:
[[[
svnadmin: E200037: Failed to parse version number string '1.3.0(null)'
svnadmin: E200004: Could not convert '0(null)' into a number
]]]

This error happens with every --pre-1.x-compatible option and is a regression
against 1.8.x introduced in r1509915 [1]. I've attached a patch to fix this
problem.

[1] http://svn.apache.org/viewvc?view=revision&revision=1509915

Thanks and regards,
Evgeny Kotkov