Fix builds with quazip 1.X

Sigh. quazip changed the lib name, include locations, etc. from version 1.
Some distributions only have 0.9. Some only  1.x and so some packages break,
so they simply patch it when building the package.

Luckily, nothing we use from quazip is affected from an API perspective.

So detect if there is quazip1, then use pkg-config to link that, else do it like before.

gui/gui.pro

@@ -7,7 +7,11 @@
 QT       += core concurrent gui network
 
 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
+
 CONFIG += c++17
+
+
+
 TARGET = looqs-gui
 TEMPLATE = app
 
@@ -69,6 +73,12 @@ else:unix: LIBS += -L$$OUT_PWD/../shared/ -lshared
 
 LIBS += -luchardet -lpoppler-qt5 -lquazip5
 
+packagesExist(quazip1-qt5) {
+	PKGCONFIG += quazip1-qt5
+	CONFIG += link_pkgconfig
+	LIBS -= -lquazip5
+}
+
 INCLUDEPATH += $$PWD/../shared
 DEPENDPATH += $$PWD/../shared