Typos in "instruments_ext.xtm"

[George]

Ben

I notice a couple of typos that should be fixed in:

external/instruments_ext.xtm#L45

in the examples:

45 ;; (set-sampler-data sampler "/tmp/piano-C.aif" 60 0 0)

and 

and also line 47

47 ;; (set-sampler-data sampler "/tmp/piano-C.aif" 60 1000 5000)

the dashes should be underscores as in the definition in line 48

48 (bind-func set_sample_data_

I know I should do a pull request but still haven't mastered that process.

Regards

George