package/jquery-datetimepicker: add .hash file

Similar to jquery-keyboard, it seems the jquery-datetimepicker tarball on the
autobuilder is corrupt.  Fix it by adding a .hash file so it falls back to
our s.b.o mirror.

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/jquery-datetimepicker/jquery-datetimepicker.hash

@@ -0,0 +1,2 @@
+# Locally calculated
+sha256 2f362a8acd149d1487a9460942f135d1037f01ee0cbfecba8c352fa2f79c34c9  jquery-datetimepicker-2.4.5.tar.gz