build: Include gio-unix-2.0

This will be needed for fd-passing by the new capture, specifically for
g_dbus_proxy_call_with_unix_fd_list().

cmake/Modules/FindGio.cmake

@@ -9,12 +9,12 @@
 # Use pkg-config to get the directories and then use these values
 # in the find_path() and find_library() calls
 find_package(PkgConfig)
-pkg_check_modules(PC_GIO gio-2.0)
+pkg_check_modules(PC_GIO gio-2.0 gio-unix-2.0)
 
 set(GIO_DEFINITIONS ${PC_GIO_CFLAGS})
 
 find_path(GIO_INCLUDE_DIRS gio.h PATHS ${PC_GIO_INCLUDEDIR} ${PC_GIO_INCLUDE_DIRS} PATH_SUFFIXES glib-2.0/gio/)
-find_library(GIO_LIBRARIES NAMES gio-2.0 libgio-2.0 PATHS ${PC_GIO_LIBDIR} ${PC_GIO_LIBRARY_DIRS})
+find_library(GIO_LIBRARIES NAMES gio-2.0 libgio-2.0 gio-unix-2.0 PATHS ${PC_GIO_LIBDIR} ${PC_GIO_LIBRARY_DIRS})
 mark_as_advanced(GIO_INCLUDE_DIRS GIO_LIBRARIES)
 
 include(FindPackageHandleStandardArgs)