Fixes typo in the Dockerfile (#193)

# Description
Docker was failing to build with: `./container.sh start orbit`, because
there was a missing `;` inside the Dockerfile. The failure was:
```
 => ERROR [orbit 3/9] RUN if [[ "${ISAACSIM_VERSION}" == "2022.2"* ]]; then         sed -i 's/\("omni.isaac.quadruped"\s=\s{}\)/"omni.isaac.quadruped" = {order = 10}/g'         /isaac-sim/apps/omni.isaac.sim.python.kit     fi                                   0.4s
------                                                                                                                                                                                                                                                                   
 > [orbit 3/9] RUN if [[ "${ISAACSIM_VERSION}" == "2022.2"* ]]; then         sed -i 's/\("omni.isaac.quadruped"\s=\s{}\)/"omni.isaac.quadruped" = {order = 10}/g'         /isaac-sim/apps/omni.isaac.sim.python.kit     fi:
0.350 /bin/sh: 1: Syntax error: end of file unexpected (expecting "fi")
------
failed to solve: process "/bin/sh -c if [[ \"${ISAACSIM_VERSION}\" == \"2022.2\"* ]]; then         sed -i 's/\\(\"omni.isaac.quadruped\"\\s=\\s{}\\)/\"omni.isaac.quadruped\" = {order = 10}/g'         ${ISAACSIM_PATH}/apps/omni.isaac.sim.python.kit     fi" did not complete successfully: exit code: 2
```

This PR adds in the `;`.

## Type of change

- Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./orbit.sh --format`
- [ ] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file

docker/Dockerfile

@@ -36,7 +36,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 # Ref: https://forums.developer.nvidia.com/t/running-a-standalone-example-with-gui-in-docker-container/248147/3
 RUN if [[ "${ISAACSIM_VERSION}" == "2022.2"* ]]; then \
         sed -i 's/\("omni.isaac.quadruped"\s=\s{}\)/"omni.isaac.quadruped" = {order = 10}/g' \
-        ${ISAACSIM_PATH}/apps/omni.isaac.sim.python.kit \
+        ${ISAACSIM_PATH}/apps/omni.isaac.sim.python.kit; \
     fi
 
 # Copy the orbit directory