Make external_db column in unmapped_object be SMALLINT UNSIGNED explicitly.

sql/patch_45_46_c.sql

+# patch_45_46_c.sql
+#
+# title: unmapped_object.external_db_id
+#
+# description:
+# Make external_db column in unmapped_object be SMALLINT UNSIGNED explicitly.
+
+ALTER TABLE external_db CHANGE COLUMN external_db_id external_db_id SMALLINT UNSIGNED;
+
+# patch identifier
+INSERT INTO meta (meta_key, meta_value) VALUES ('patch', 'patch_45_46_c.sql|unmapped_object.external_db_id');
+
+
+