Gay Sinclair has been selling off many of the buildings she owns in and around East Village. The one she says she’ll never give up is the historic Wonder Bread building. Yet she might not have a choice. If Measure C passes, there’s a chance the city could use eminent domain to force Sinclair to accept a deal and clear the way for a convadium. It wouldn’t be the first time she’s been forced to surrender a historic building for a stadium.