ERROR: must be owner of extension plpgsql

Today while moving Django/PostgreSQL site between servers and importing an SQL
dump into the new location I got a surprising error " ERROR: must be owner
of extension plpgsql". I'm already used to PostgreSQL quirks so after a
quick search I came to the following solution: Login as postgres user and do:

psql template1

then:

alter role your_role_name with superuser;

That will make your current user as superuser and give him permissions to own
plpgsql language.