Do not install icon cache upon staged install

[super7ramp]

Upon installation, updating icon cache is relevant so that new icons can be found by the system.

Upon a staged installation though, i.e. when DESTDIR is set to a staging installation area, it is not relevant to update the icon cache as this cache is not the actual target system's cache.

Staged installation is typically used when creating a package of the application. Cache update is a problem well known to packagers which typically handle it by wrapping cache update commands into scripts to be executed at post (un)installation time - on the real target system.

See also:

• 703

• The tutorial referenced in the ticket which actually mentions this tricky staged install case

[vslavik]

Thank you for setting me straight (I misunderstood the purpose of this bit), and thank you for the fix!