BitTorrent code still relying on QtWebKit

[pmattern]

Parts of the BitTorrent code are still relying on QWebView of QtWebkit as building fails on systems lacking QtWebKit with

[ 72%] Building CXX object CMakeFiles/fatrat.dir/src/tools/TorrentSearch.cpp.o
In file included from /usr/local/peter/Tests/FatRat/Projekt/fatrat/src/tools/TorrentWebView.h:32:0,
from /usr/local/peter/Tests/FatRat/Projekt/fatrat/src/tools/TorrentSearch.cpp:35:
/usr/local/peter/Tests/FatRat/Projekt/build/ui_TorrentWebView.h:13:36: fatal error: QtWebKitWidgets/QWebView: No such file or directory
#include <QtWebKitWidgets/QWebView>
^
compilation terminated.
make[2]: *** [CMakeFiles/fatrat.dir/build.make:2865: CMakeFiles/fatrat.dir/src/tools/TorrentSearch.cpp.o] Error 1
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [CMakeFiles/Makefile2:100: CMakeFiles/fatrat.dir/all] Error 2
make: *** [Makefile:128: all] Error 2

but succeeds after adding the QtWebKit development files.

Given that QtWebKit will probably be dropped one day QWebView should be replaced completely with QWebEngineView in the long run.