revert error handler to no longer take filenames
revert error handler to no longer take filenames

ryanluker/vscode-coverage-gutters,ryanluker/vscode-coverage-gutters,ryanluker/vscode-coverage-gutters,ryanluker/vscode-coverage-gutters,ryanluker/vscode-coverage-gutters,ryanluker/vscode-coverage-gutters,ryanluker/vscode-coverage-gutters,ryanluker/vscode-coverage-gutters,ryanluker/vscode-coverage-gutters