libfcgi: needs mmu

Fixes:
http://autobuild.buildroot.net/results/93a/93a7f816b5c70a247491063ca733b537ee7aec65/

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/libfcgi/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_LIBFCGI
 	bool "libfcgi"
+	depends on BR2_USE_MMU # fork()
 	help
 	  FCGI, a fastcgi developer library for C/C++