fix: gracefully explode of missing context

See toolshed/abra#675

tests/integration/app_deploy.bats

@@ -577,3 +577,18 @@ teardown(){
   assert_success
   refute_output --partial "IMAGES"
 }
+
+# bats test_tags=slow
+@test "manually created server without context bails gracefully" {
+  run mkdir -p "$ABRA_DIR/servers/default2"
+  assert_success
+  assert_exists "$ABRA_DIR/servers/default2"
+
+  run cp "$ABRA_DIR/servers/$TEST_SERVER/$TEST_APP_DOMAIN.env" "$ABRA_DIR/servers/default2/$TEST_APP_DOMAIN_2.env"
+  assert_success
+  assert_exists "$ABRA_DIR/servers/default2/$TEST_APP_DOMAIN_2.env"
+
+  run $ABRA app deploy "$TEST_APP_DOMAIN_2" --no-input --no-converge-checks
+  assert_failure
+  assert_output --partial "server missing context"
+}