delete-swis: Account for Bug836028 in deletion of swis

'flash:/EOS.swi' or 'flash:EOS.swi' are possible boot image values.
Account for this in the script to avoid deletion of boot image
accidentally

Change-Id: Ie97c3500b22cbb57bb8931d8beae88efb1bbe834

delete-swis-action-pack/config.yaml

@@ -1,4 +1,4 @@
 type: PACKAGE
-version: 1.1.0
+version: 1.1.1
 name: delete-swis Action package
 description: Action package containing a script that deletes all unused EOS images on /mnt/flash

delete-swis-action-pack/delete-swis/script.py

@@ -17,9 +17,12 @@
 showbootResp = cmdOut[1]["response"]
 # Show boot response is a dict. The eos boot image is under 'softwareImage'
 eosBootImageFull = showbootResp["softwareImage"]
-# The eos boot image is in the form of 'flash:/EOS.swi'. Only the image name is of interest,
-# so split on the / to get 'EOS.swi'
-eosBootImage = eosBootImageFull.split("/")[1]
+# The eos boot image is in the form of either 'flash:/EOS.swi' or 'flash:EOS.swi'.
+# Only the image name is of interest, so split on the common ':' to get 'EOS.swi' part
+# and parse further if needed
+eosBootImage: str = eosBootImageFull.split(':')[1]
+if eosBootImage.startswith('/'):
+    eosBootImage = eosBootImage[1:]
 
 # This command returns a large response message
 cmdOut = ctx.runDeviceCmds(["enable", "dir flash:EOS*"])