rdesktop: needs mmu

Fixes:
http://autobuild.buildroot.net/results/8f2/8f24a81516383feaffed485c85958e7a1c68176c/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/rdesktop/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_RDESKTOP
 	bool "rdesktop"
+	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_OPENSSL
 	select BR2_PACKAGE_XLIB_LIBX11
 	select BR2_PACKAGE_XLIB_LIBXT