Changed the printing of MethodError

MethodError printed "no method f(DataType)" for if it couldn't find a
method for the concrete datatype, eaven tough there were methods
available for other datatypes. This pathch changes the printing from
DataType to Type{MyType} instead.

fix #4825
Small typo
Merge pull request #4835 from ivarne/no_method_error

Changed the printing of MethodError