omit runc connector from darwin build

cursor.go

@@ -8,11 +8,6 @@ import (
 	ui "github.com/gizak/termui"
 )
 
-var enabledConnectors = map[string]func() connector.Connector{
-	"docker": connector.NewDocker,
-	"runc":   connector.NewRunc,
-}
-
 type GridCursor struct {
 	selectedID  string // id of currently selected container
 	filtered    container.Containers
@@ -20,12 +15,6 @@ type GridCursor struct {
 	isScrolling bool // toggled when actively scrolling
 }
 
-func NewGridCursor(connectorName string) *GridCursor {
-	return &GridCursor{
-		cSource: enabledConnectors[connectorName](),
-	}
-}
-
 func (gc *GridCursor) Len() int { return len(gc.filtered) }
 
 func (gc *GridCursor) Selected() *container.Container {