Fixed compatibility issue for CSR upgrade

Older version was crashing with "Unsupported IP Protocol Type" message. Changed to add some XML filtering to fix (as copied from other samples in this repo).
Also changed the sytnax of one print statement so that it works with both Python 2.7 and 3.x.

Author: WendellOdom

NC-get-config/NC-get-config.py

@@ -24,7 +24,7 @@
 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 #
-# This script retrieves entire configuration from a network element via NETCONF 
+# This script retrieves entire configuration from a network element via NETCONF
 # prints it out in a "pretty" XML tree.
 
 import sys
@@ -44,14 +44,20 @@
     parser.add_argument('--port', type=int, default=830,
                         help="Specify this if you want a non-default port")
     args = parser.parse_args()
-    
+
     m =  manager.connect(host=args.host,
                          port=args.port,
                          username=args.username,
                          password=args.password,
                          device_params={'name':"csr"})
-       # Pretty print the XML reply
-    xmlDom = xml.dom.minidom.parseString( str( m.get_config(source='running')))
-    print xmlDom.toprettyxml( indent = "  " )
 
+    hostname_filter = '''
+                      <filter>
+                          <native xmlns="http://cisco.com/ns/yang/Cisco-IOS-XE-native">
+                          </native>
+                      </filter>
+                      '''
 
+       # Pretty print the XML reply
+    xmlDom = xml.dom.minidom.parseString( str( m.get_config('running', hostname_filter)))
+    print(xmlDom.toprettyxml( indent = "  " ))