Remove duplicate value

Author: anonychun

railties/lib/rails/generators/rails/app/templates/docker-entrypoint.tt

@@ -2,7 +2,7 @@
 
 # Enable jemalloc for reduced memory usage and latency.
 if [ -z "${LD_PRELOAD+x}" ] && [ -f /usr/lib/*/libjemalloc.so.2 ]; then
-  export LD_PRELOAD="$(echo /usr/lib/*/libjemalloc.so.2) $LD_PRELOAD"
+  export LD_PRELOAD="$(echo /usr/lib/*/libjemalloc.so.2)"
 fi
 
 <% unless skip_active_record? -%>