Revert "Fix rebuild-ui.sh script (jaegertracing#6098)"

This reverts commit 32112eb.

scripts/rebuild-ui.sh

@@ -7,10 +7,7 @@ set -euxf -o pipefail
 
 cd jaeger-ui
 
-if [[ "$(git rev-parse --is-shallow-repository)" == "true" ]]; then
-    git fetch --unshallow
-fi
-git fetch --all --tags
+git fetch --all --unshallow --tags
 git log --oneline --decorate=full -n 10 | cat
 
 last_tag=$(git describe --tags --dirty 2>/dev/null)