Carbohydrate Sequence Build Downloads Sometimes Incomplete

**Tool:**
Back-end for the various glycan sequence entry points.

**Bug Description:**
Sometimes the "download all" zip file is produced before the minimization finishes.

**To Reproduce:**
Use one of the sequence generating/receiving entry points. Go to the downloads page. Click the "download all" button. Unzip the file and navigate to one of the build directories inside 'Requested_Builds". If the build is not complete, there will not be a file called 'min-gas.restrt.nc'.

**Expected behavior**
The zip file should not be generated until after the minimization is complete.