curl: make sure openssl isn't tried when the openssl package isn't enabled

Works around build errors caused by broken Xorg dependencies.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
diff --git a/package/libcurl/libcurl.mk b/package/libcurl/libcurl.mk
index fb04da0..44c2317 100644
--- a/package/libcurl/libcurl.mk
+++ b/package/libcurl/libcurl.mk
@@ -19,6 +19,8 @@
 # are found first.
 LIBCURL_CONF_ENV += LD_LIBRARY_PATH=$$LD_LIBRARY_PATH:/lib:/usr/lib
 LIBCURL_CONF_OPT += --with-ssl=$(STAGING_DIR)/usr --with-random=/dev/urandom
+else
+LIBCURL_CONF_ENV += --without-ssl
 endif
 
 $(eval $(call AUTOTARGETS,package,libcurl))