[libcalamares] Avoid warnings from MOC-generated code

- Moc generates Q_UNUSED(_a); which in turn (with clang) issues
   a superfluous-semicolon warning. Existing code with automoc
   uses utils/moc-warnings.h to turn off warnings that are issued
   on moc code. Include it explicitly here because automoc isn't
   applied.

src/libcalamares/modulesystem/Tests.cpp

@@ -130,4 +130,5 @@ ModuleSystemTests::testBadFromStringCases()
 
 QTEST_GUILESS_MAIN( ModuleSystemTests )
 
+#include "utils/moc-warnings.h"
 #include "Tests.moc"

src/libcalamares/network/Manager.cpp

@@ -285,4 +285,5 @@ Manager::asynchronouseGet( const QUrl& url, const CalamaresUtils::Network::Reque
 }  // namespace Network
 }  // namespace CalamaresUtils
 
+#include "utils/moc-warnings.h"
 #include "Manager.moc"