Improve error message for "Error (log id: 312889): Error tokenizing data. C error: Expected 3 fields in line 10, saw 5"

In other works, make it more user friendly. Perhaps go with:
"Your file has more or less columns than headers; this is a common problem with Excel files. To fix, select the empty columns after your data and deleting them (even if they seem empty already) and do the same with the rows; they upload and try again."