Remove field dbprimary_acc_linkable from external_db table.

sql/patch_62_63_c.sql

+# patch_62_63_c.sql
+#
+# Title: Remove field dbprimary_acc_linkable from external_db table.
+#
+# Description:
+# Field is obsolete.
+
+ALTER TABLE external_db DROP dbprimary_acc_linkable;
+
+# Patch identifier
+INSERT INTO meta (species_id, meta_key, meta_value)
+  VALUES (NULL, 'patch', 'patch_62_63_c.sql|remove_dbprimary_acc_linkable');