schema: wrap upgrade scripts in transaction blocks

schema/versions/mysql/71.sql

@@ -1,3 +1,7 @@
+begin;
+
 insert into ttrss_filter_types (id,name,description) values (7, 'tag', 'Article Tags');
 
 update ttrss_version set schema_version = 71;
+
+commit;

schema/versions/mysql/72.sql

@@ -1,5 +1,9 @@
+begin;
+
 alter table ttrss_user_entries add column tag_cache text;
 update ttrss_user_entries set tag_cache = '';
 alter table ttrss_user_entries change tag_cache tag_cache text not null;
 
 update ttrss_version set schema_version = 72;
+
+commit;

schema/versions/pgsql/71.sql

@@ -1,3 +1,7 @@
+begin;
+
 insert into ttrss_filter_types (id,name,description) values (7, 'tag', 'Article Tags');
 
 update ttrss_version set schema_version = 71;
+
+commit;

schema/versions/pgsql/72.sql

@@ -1,5 +1,9 @@
+begin;
+
 alter table ttrss_user_entries add column tag_cache text;
 update ttrss_user_entries set tag_cache = '';
 alter table ttrss_user_entries alter column tag_cache set not null;
 
 update ttrss_version set schema_version = 72;
+
+commit;