TORONTO — Following the Obama administration’s rejection of the Keystone XL pipeline, the oil industry faces the tricky task of making sure the crude oil targeted for the pipeline still gets where it needs to go. The pipeline, first proposed by TransCanada Corp. in 2008, was projected to carry 800,000 barrels a day of crude from Canada and North Dakota down to Nebraska, where existing pipelines would bring it to refineries on the Gulf Coast. Keystone XL was expected to come online toward the end of this decade.