vcl PDF export: remove no longer direct curl dependency

The relevant code has been moved to svl.

Change-Id: Ib635de3ec541d2ef3b7f54071d444356ef076711
Reviewed-on: https://gerrit.libreoffice.org/41745
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>

vcl/Library_vcl.mk

@@ -56,8 +56,6 @@ $(eval $(call gb_Library_use_custom_headers,vcl,\
 ))
 
 $(eval $(call gb_Library_use_externals,vcl,\
-	$(if $(filter LINUX MACOSX ANDROID %BSD SOLARIS,$(OS)), \
-		curl) \
 	jpeg \
 	libeot \
 	$(if $(filter PDFIUM,$(BUILD_TYPE)),pdfium) \