don't fail if no required bootloaders are defined

Generic targets don't have a list of defined bootloaders.  Instead of
failing to build an OTA package, just omit the constraint.

Fix bad references to ExternalError.
1 file changed
tree: cf99f8fcfb2a55ebd2b96ae683c39b0b8c2c963d
  1. core/
  2. libs/
  3. target/
  4. tools/
  5. buildspec.mk.default
  6. cleanspec.mk
  7. envsetup.sh