testing/liblastfm-qt: riscv64 build fails

https://build.alpinelinux.org/buildlogs/build-edge-riscv64/testing/liblastfm-qt/liblastfm-qt-1.1.10_git20190823-r0.log

[ 93%] Building CXX object tests/CMakeFiles/UrlBuilderTest.dir/TestUrlBuilder.cpp.o
In file included from /home/buildozer/aports/testing/liblastfm-qt/src/liblastfm-2ce2bfe1879227af8ffafddb82b218faff813db9/src/fingerprint/Fingerprint.cpp:21:
/home/buildozer/aports/testing/liblastfm-qt/src/liblastfm-2ce2bfe1879227af8ffafddb82b218faff813db9/src/fingerprint/Fingerprint.h:74:49: error: ISO C++17 does not allow dynamic exception specifications
   74 |         void generate( FingerprintableSource* ) throw( Error );
      |                                                 ^~~~~
/home/buildozer/aports/testing/liblastfm-qt/src/liblastfm-2ce2bfe1879227af8ffafddb82b218faff813db9/src/fingerprint/Fingerprint.h:85:86: error: ISO C++17 does not allow dynamic exception specifications
   85 |         void decode( QNetworkReply*, bool* lastfm_needs_a_complete_fingerprint = 0 ) throw( Error );
      |                                                                                      ^~~~~