liblastfm 1.0.3 dependency introduced in fb28edf000

[Sam]

I'm pretty sure this was accidental, but older versions of liblastfm1
don't have lastfm::XmlQuery::parse(QNetworkReply*&), leading to build
errors. Not all distros have 1.0.3, so we should probably fix it to
support older versions. Here's the log:

[12:27:02] [ 98%] Building CXX object
src/services/lastfm/CMakeFiles/amarok_service_lastfm.dir/LastFmTreeModel.o
[12:27:03] /home/sam/devel/amarok/src/services/lastfm/LastFmTreeModel.cpp:
In member function ‘void LastFmTreeModel::slotAddTopArtists()’:
[12:27:03] /home/sam/devel/amarok/src/services/lastfm/LastFmTreeModel.cpp:197:26:
error: no matching function for call to
‘lastfm::XmlQuery::parse(QNetworkReply*&)’
[12:27:03] /home/sam/devel/amarok/src/services/lastfm/LastFmTreeModel.cpp:197:26:
note: candidate is:
[12:27:03] /usr/include/lastfm/XmlQuery.h:46:14: note: bool
lastfm::XmlQuery::parse(const QByteArray&)
[12:27:03] /usr/include/lastfm/XmlQuery.h:46:14: note:   no known
conversion for argument 1 from ‘QNetworkReply*’ to ‘const QByteArray&’
[12:27:03] make[2]: ***
[src/services/lastfm/CMakeFiles/amarok_service_lastfm.dir/LastFmTreeModel.o]
Error 1
[12:27:03] make[1]: ***
[src/services/lastfm/CMakeFiles/amarok_service_lastfm.dir/all] Error 2
[12:27:03] make: *** [all] Error 2
[12:27:03] process ended with code 2
[12:27:03] terminated with error, aborting