package/erlang: disable for static builds

erlang wants to build shared libs, always.

So, disable erlang when we're building static-only.

Fixes:
    http://autobuild.buildroot.net/results/1ce/1ceaa6925d1ded236d01ae9feb31f5f915f6b51a/

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Frank Hunleth <fhunleth@troodon-software.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/erlang/Config.in

@@ -1,10 +1,11 @@
-comment "erlang needs a toolchain w/ threads"
-	depends on !BR2_TOOLCHAIN_HAS_THREADS
+comment "erlang needs a toolchain w/ threads, shared library"
+	depends on !BR2_TOOLCHAIN_HAS_THREADS && BR2_PREFER_STATIC_LIB
 
 config BR2_PACKAGE_ERLANG
 	bool "erlang"
 	depends on BR2_USE_MMU # fork()
 	depends on BR2_TOOLCHAIN_HAS_THREADS
+	depends on !BR2_PREFER_STATIC_LIB
 	help
 	  Erlang is a programming language used to build massively scalable
 	  soft real-time systems with requirements on high availability.