Adjust path.

python-qt5.spec

@@ -306,7 +306,7 @@ pushd %{_target_platform}-python3
   %{?py3_sip:--sip=%{_bindir}/python3-sip} \
   %{?py3_sipdir:--sipdir=%{py3_sipdir}} \
   --verbose \
-  --sip-incdir %{_prefix}/include/python%{python3_version}/ \
+  --sip-incdir /usr/include/python%{python3_version}/ \
   --dbus=/usr/include/dbus-1.0/ \
   QMAKE_CFLAGS_RELEASE="%{optflags}" \
   QMAKE_CXXFLAGS_RELEASE="%{optflags} -I/usr/%{_lib}/dbus-1.0/include/" \