The word "it" refers to the land, which refers to the people of the land. Alternate translation: "the people of the land will not be proud anymore that they are strong" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This can be stated in active form. Alternate translation: "no one will live in the mountains of Israel" (See: [[rc://en/ta/man/translate/figs-activepassive]])