If we're running webpack dev server, skip the client build on startup.

scripts/common_startup.sh

@@ -18,6 +18,7 @@ CREATE_VENV=1
 REPLACE_PIP=$SET_VENV
 COPY_SAMPLE_FILES=1
 SKIP_CLIENT_BUILD=${GALAXY_SKIP_CLIENT_BUILD:-0}
+CLIENT_DEV_SERVER=${GALAXY_CLIENT_DEV_SERVER:-0}
 NODE_VERSION=${GALAXY_NODE_VERSION:-"$(cat client/.node_version)"}
 
 for arg in "$@"; do
@@ -32,6 +33,11 @@ for arg in "$@"; do
     [ "$arg" = "--skip-client-build" ] && SKIP_CLIENT_BUILD=1
 done
 
+# If a client dev server is being configured, skip the client build.
+if [ $CLIENT_DEV_SERVER -ne 0 ]; then
+    SKIP_CLIENT_BUILD=1
+fi
+
 SAMPLES="
     lib/tool_shed/scripts/bootstrap_tool_shed/user_info.xml.sample
     tool-data/shared/ucsc/builds.txt.sample