fdo#70393: move unixODBC to a subdir of external

Change-Id: I191b75802eba781fc62ab21cd41918983a6efdb0
Reviewed-on: https://gerrit.libreoffice.org/6569
Reviewed-by: David Tardon <dtardon@redhat.com>
Tested-by: David Tardon <dtardon@redhat.com>

RepositoryExternal.mk

@@ -116,7 +116,7 @@ else
 
 define gb_LinkTarget__use_odbc_headers
 $(call gb_LinkTarget_set_include,$(1),\
-	-I$(SRCDIR)/unixODBC/inc \
+	-I$(SRCDIR)/external/unixODBC/inc \
 	$$(INCLUDE) \
 )