midgard_object_update: set internal error only if update failed and no error is set
midgard_object_update: set internal error only if update failed and no
error is set

piotras/midgard-core,midgardproject/midgard-core,piotras/midgard-core,piotras/midgard-core,midgardproject/midgard-core,piotras/midgard-core,midgardproject/midgard-core,midgardproject/midgard-core