Bump copyright year

debian/copyright

docs/conf.py

shared/com.github.hluk.copyq.appdata.xml

src/app/app.cpp

src/app/app.h

src/app/applicationexceptionhandler.cpp

src/app/applicationexceptionhandler.h

src/app/clipboardclient.cpp

src/app/clipboardclient.h

src/app/clipboardmonitor.cpp

src/app/clipboardmonitor.h

src/app/clipboardownermonitor.cpp

src/app/clipboardownermonitor.h

src/app/clipboardserver.cpp

src/app/clipboardserver.h

src/common/action.cpp

src/common/action.h

src/common/actionoutput.cpp

src/common/actionoutput.h

src/common/actiontablemodel.cpp