QT doesn't need svg

It looks like QT doesn't need svg here.  This causes the binary to attempt linking to qtsvg, however, since gqrx doesn't actually use qtsvg, this seems kinda silly.

the downstream bug is here:
https://bugs.gentoo.org/show_bug.cgi?id=521206

Are we missing something?
Merge pull request #195 from ZeroChaos/patch-1

QT doesn't need svg