plugins: python renderer: Fix broken code due to merge. Functions of plugins now have to be exported explicitly.

plugins/python-renderer/src/force-fork.c

@@ -29,6 +29,9 @@
 
 #include <gds-render/output-renderers/external-renderer-interfaces.h>
 
-const int VAR_DECL(EXTERNAL_LIBRARY_FORK_REQUEST) = 0;
+/* The precense of this variable tells the gds-render application to execute this plugin in a separate process
+ * The variable's value is don't care
+ */
+const int EXPORTED_VAR_DECL(EXTERNAL_LIBRARY_FORK_REQUEST) = 1;
 
 /** @} */