Elsewise you can disable UPNP with --without-miniupnpc as argument to configure
For a Qt Creator/qmake build (as opposed to a later Core 0.9+ autotools build), the flags are:
qmake "USE_UPNP=1" (enabled by default; default)
qmake "USE_UPNP=0" (disabled by default)
qmake "USE_UPNP=-" (not supported)
:
So,
"USE_UPNP=-" is what you need, it switches off the requirement for miniupnpc headers/libs
Cheers
Graham