OTTAWA, April 17 (Reuters) - Some 155,000 public workers in Canada will go on strike at midnight on Wednesday if they are unable to reach a wage deal with the federal government, the leader of the Public Service Alliance of Canada (PSAC) union said on Monday. PSAC President Chris Aylward said he was "setting a clock on this round of bargaining" and that a strike would be called if there is no deal by 9 p. See here for a complete list of exchanges and delays