python-schedule: add missing hash type

Fixes the following check-package warning:

./package/python-schedule/python-schedule.hash:5: expected three fields (http://nightly.buildroot.org/#adding-packages-hash)
./package/python-schedule/python-schedule.hash:5: unexpected type of hash (http://nightly.buildroot.org/#adding-packages-hash)

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/python-schedule/python-schedule.hash

@@ -2,4 +2,4 @@
 md5	ab135a73458547d2b836beddd168528b  schedule-0.4.3.tar.gz
 sha256	31a160546a17838842199c792ba267575cf41339ca730aaf060567b798f4f46e  schedule-0.4.3.tar.gz
 # License file, locally calculated
-30a8352c318ce1b645acde0299697342d4380ed2637d7ca18a8ad25661e3b41b  LICENSE.txt
+sha256	30a8352c318ce1b645acde0299697342d4380ed2637d7ca18a8ad25661e3b41b  LICENSE.txt