SoupConnection: drop "message" property
SoupConnection: drop "message" property

epiphany-extensions is dead, so there's no reason to support the
undocumented SoupConnection:message property for soup-fly any more.

fanc999/libsoup,fanc999/libsoup,Distrotech/libsoup,jwendell/libsoup,jwendell/libsoup,jwendell/libsoup,jwendell/libsoup,Distrotech/libsoup,Distrotech/libsoup,fanc999/libsoup,Distrotech/libsoup,Distrotech/libsoup,fanc999/libsoup,jwendell/libsoup,fanc999/libsoup