proc: avoid dup chan recv breakpoints
proc: avoid dup chan recv breakpoints

I encountered the error message described in the issue while debugging
InfluxDB. I can confirm that after this fix the error disapeared.

Fixes #258

dlsniper/delve,derekparker/delve,go-delve/delve,aarzilli/delve,dr2chase/delve,go-delve/delve,ignatov/delve,ggndnn/delve,visualfc/delve,alexbrainman/delve,visualfc/delve,go-delve/delve,ignatov/delve,alexbrainman/delve,ggndnn/delve,go-delve/delve,derekparker/delve,dr2chase/delve,go-delve/delve,aarzilli/delve,derekparker/delve,alexbrainman/delve,visualfc/delve,dr2chase/delve,aarzilli/delve,dlsniper/delve,ignatov/delve,aarzilli/delve,dlsniper/delve,ggndnn/delve