closes bpo-32460: ensure all non-static globals have initializers (#5061)

diff --git a/Modules/_sqlite/microprotocols.c b/Modules/_sqlite/microprotocols.c
index 2261b80..3d01872 100644
--- a/Modules/_sqlite/microprotocols.c
+++ b/Modules/_sqlite/microprotocols.c
@@ -33,7 +33,7 @@
 
 /** the adapters registry **/
 
-PyObject *psyco_adapters;
+static PyObject *psyco_adapters = NULL;
 
 /* pysqlite_microprotocols_init - initialize the adapters dictionary */