Fix CT_SanitizePath

Replace the over-engineered and buggy test in CT_SanitizePath
with a straight forward string pattern match, and also
handle empty PATH elements which are qeuivalent to ".".

Thanks-To: Arnaud Lacombe <lacombar@gmail.com>
Signed-off-by: Johannes Stezenbach <js@sig21.net>

menu "Debug facilities"

source "config.gen/debug.in"

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