When a .gitmodules file exists but is empty then devtool finish fails.
Add an additional check for this.
[YOCTO #14999]
(From OE-Core rev: b4f0f7c4934bade9e4d4a1086f9d8b29d8e9ad45)
Signed-off-by: Thomas Roos <throos@amazon.de>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>