The ccache port should have "configure.ccache no"

[szhorvat (Szabolcs Horvát)]

After the last update (just a rev bump, ​https://github.com/macports/macports-ports/commit/d6844634ee354f5e7709903b16f44312c28316ee), ccache failed to build for me. It turns out that this happened because I had configureccache yes in my MacPorts configuration, so building ccache tried to use ccache itself. However, entire reason ccache had to be updated (actually just rebuilt) was that it became broken due to a library update. The error was:

dyld: Library not loaded: /opt/local/lib/libhiredis.0.14.dylib

Suggestion:

Please disable using ccache when building ccache itself, to avoid this kind of trouble in the future.