travis: upload JARs and deploy from UPLOAD builds only

Author: stephengold

.travis.yml

@@ -36,7 +36,6 @@ matrix:
       - ./gradlew -PbuildNativeProjects=true jme3-android-native:assemble jme3-bullet-native-android:assemble
     after_success:
       - '[ "$TRAVIS_PULL_REQUEST" == "false" ] && ./private/upload_native.sh || :'
-      - '[ -n "$TRAVIS_TAG" ] && [ "$TRAVIS_PULL_REQUEST" == "false" ] && ./gradlew bintrayUpload || :'
 
 addons:
   ssh_known_hosts: github.com
@@ -89,6 +88,7 @@ deploy:
   file: "${RELEASE_DIST}"
   skip_cleanup: true
   on:
+    condition: $UPLOAD = true
     repo: jMonkeyEngine/jmonkeyengine
     tags: true