Any city in this state, that has heretofore deeded, or may hereafter deed, to the state of Minnesota any lands to be used by the state for a public purpose in such deed stated, conditioned, among other things, that such lands shall be so used by the state for a period of time, which time exceeds 20 years, and in case such use is not made thereof for the stated time, then such land shall revert to such city, may at any time after 15 years from the date of the deed by a majority vote of the city council at any regular meeting thereof, or at a properly called special meeting of such council, pass a resolution or enact an ordinance modifying the terms and conditions above specified and permit the noncompliance by the state with such terms and conditions as originally made, either wholly or in part, and such resolution so adopted shall operate as a release of the state from such terms and conditions to the extent provided in such resolution and the action by the state in conformity with such resolution shall not in any way cause a reversion to such city of the lands or any part thereof or interest therein.