Allow ICU_PATH path-constant in project-config to work.

It is only affecting build if not ICU_PATH is set on command line.


[SVN r52176]

libs/regex

@@ -1 +1 @@
-Subproject commit 3e62631ecb3cbbdce13a91ecaa8b3170802a6a3f
+Subproject commit 6f7f8a688617417dac61c0a6387d3474d844e88c