The 1837 edition accidentally replaced the correct there with they, probably because of the preceding they in the sentence (“yea they could not bear that …”). This obvious typo was nonetheless copied into the 1841 British edition but was removed from the text in the third edition (1840) and in the 1849 LDS edition. Of course, the critical text will maintain the correct there.
Summary: Maintain the occurrence of there in Alma 48:25 (“so long as there were any who should keep the commandments of God”).