Round box position to integer when pasting embedded color

[radarhere]

Resolves #6515

If align="center" is used for multiline_text,

Pillow/src/PIL/ImageDraw.py

Lines 562 to 570 in 4c59f77

	elif align == "center":
	left += width_difference / 2.0
	elif align == "right":
	left += width_difference
	else:
	raise ValueError('align must be "left", "center" or "right"')
	self.text(
	(left, top),

then coord can be a float for the embedded_color paste. But when pasting one image onto another, the co-ordinates must be integers, and so an error will be raised, as in the issue.

Pillow/src/PIL/ImageDraw.py

Line 486 in 4c59f77

self.im.paste(color, coord + coord2, mask)

This PR rounds the co-ordinates to integers in that case.

[nulano]

I've created radarhere#18 with a few suggestions.

[nulano]

The alternative image is for Centos 7, for some reason the Codecov processing failed for that one coverage report: