dev-util/idea-community: fix custom-jdk useflag in previous versions

dev-util/idea-community: fix custom-jdk useflag in previous versions

Because of the switch to a 64 bit jdk at some point prior to even 2017.2.2 (the
oldest version in the tree), the directory naming changed and so even without
the custom-jdk useflag the jdk was being installed, and with the custom-jdk
useflag the jdk's binaries were not correctly being marked executable

Package-Manager: Portage-2.3.58, Repoman-2.3.12
Signed-off-by: Kyle Elbert <kcelbert@gmail.com>
Signed-off-by: Alice Ferrazzi <alicef@gentoo.org>