Fix the default DMA in python code (#266)

DMA 5 causes file system errors on PI 3

python/neopixel.py

@@ -50,13 +50,13 @@ def __setitem__(self, pos, value):
 
 
 class Adafruit_NeoPixel(object):
-	def __init__(self, num, pin, freq_hz=800000, dma=5, invert=False,
+	def __init__(self, num, pin, freq_hz=800000, dma=10, invert=False,
 			brightness=255, channel=0, strip_type=ws.WS2811_STRIP_RGB):
 		"""Class to represent a NeoPixel/WS281x LED display.  Num should be the
 		number of pixels in the display, and pin should be the GPIO pin connected
 		to the display signal line (must be a PWM pin like 18!).  Optional
 		parameters are freq, the frequency of the display signal in hertz (default
-		800khz), dma, the DMA channel to use (default 5), invert, a boolean
+		800khz), dma, the DMA channel to use (default 10), invert, a boolean
 		specifying if the signal line should be inverted (default False), and
 		channel, the PWM channel to use (defaults to 0).
 		"""