erlang: odbc support requires thread support

Fixes:

  http://autobuild.buildroot.net/results/cba60679fa916128796a7b4131ed50403bc74798/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/erlang/erlang.mk

@@ -55,8 +55,12 @@ else
 ERLANG_CONF_OPTS += --without-ssl
 endif
 
-ifeq ($(BR2_PACKAGE_UNIXODBC),y)
+# ODBC support in erlang requires threads
+ifeq ($(BR2_PACKAGE_UNIXODBC)$(BR2_TOOLCHAIN_HAS_THREADS),yy)
 ERLANG_DEPENDENCIES += unixodbc
+ERLANG_CONF_OPTS += --with-odbc
+else
+ERLANG_CONF_OPTS += --without-odbc
 endif
 
 ifeq ($(BR2_PACKAGE_ZLIB),y)