backflip-from-tsv: Ignore commas in spreadsheet.

They would confuse the parser, so just get rid of them.

Change-Id: I1328d137d6924cdceedfdd05e49c8e1c29f4ceb0
diff --git a/backflip-from-tsv b/backflip-from-tsv
index 1eb2c90..f7653df 100755
--- a/backflip-from-tsv
+++ b/backflip-from-tsv
@@ -145,7 +145,7 @@
 	    echo "Unsupported line $svn"
 	    ;;
     esac
-done < <(sed 's/	/,/g')
+done < <(sed -e 's/,//g' -e 's/	/,/g')
 
 # Sort the keys, to process them in order, so that we can build the
 # union of the stacks in case of overlap