pegasus.transfer.bypass.input.staging breaks symlinking on the local site

In order to run on OSG, we need to set
```
pegasus.transfer.bypass.input.staging=True
```
however this breaks symlinking on the local site. Without this option set, local jobs can access their frame data with symlinks:
```
 { "type": "transfer",
   "id": 1,
   "src_urls": [
     { "site_label": "local", "url": "file:///home/dbrown/projects/osg/local-workflow-1/output/local-site-scratch/work/./main_ID0000001/./113494/H-H1_HOFT_C02-1134940160-4096.gwf", "checkpoint": "false" }
   ],
   "dest_urls": [
     { "site_label": "local", "url": "symlink://$PWD/113494/H-H1_HOFT_C02-1134940160-4096.gwf" }
   ] }
```

However, when I set this, these become copy jobs:
```
 { "type": "transfer",
   "id": 1,
   "src_urls": [
     { "site_label": "local", "url": "file:///cvmfs/oasis.opensciencegrid.org/ligo/frames/O1/H1_HOFT_C02/H/1134/H-H1_HOFT_C02-1134940160-4096.gwf", "priority": 400, "checkpoint": "false" },
   ],
   "dest_urls": [
     { "site_label": "local", "url": "file://$PWD/113494/H-H1_HOFT_C02-1134940160-4096.gwf" }
   ] }

This is a blocker for us using OSG.