Better handling errors when fitting Cyclops model during positive control synthesis

[k-m-li]

Sometimes fitCyclopsModel returns an error message, hence the tryCatch(fitCyclopsModel) returns a character vector on which the $ operator is invalid (cannot access fit$returnFlag)

We should check if fit is a character object first.

MethodEvaluation/R/PositiveControlSynthesis.R

Lines 853 to 868 in 7898881

	fit <- tryCatch(
	{
	Cyclops::fitCyclopsModel(cyclopsData, prior = prior, control = control)
	},
	error = function(e) {
	e$message
	}
	)
	if (fit$return_flag != "SUCCESS") {
	fit <- fit$return_flag
	}
	if (is.character(fit)) {
	ParallelLogger::logInfo(paste("Unable to fit model for outcome", task$outcomeId, ":", fit))
	dir.create(task$modelFolder)
	write.csv(fit, file.path(task$modelFolder, "Error.txt"))
	} else {