Somebody has changed the pronunciation back to [ˌmɪsɪˈsɔːɡə]. I do not think an American/British English pronunciation will suffice for a CANADIAN city, so this time when I change it, I don't want some ignorant American changing it back. I am Canadian and I pronounce it [ˌmɪsɪˈsɑːɡə] NOT [ˌmɪsɪˈsɔːɡə]. Every native English speaker I know who is from Canada also pronounces it [ˌmɪsɪˈsɑːɡə].