use dialect-agnostic regexes in onos scripts

Change-Id: Ifd828fd2bc130598d796ac4d786c77ba31365d8e
diff --git a/tools/dev/bin/onos-setup-karaf b/tools/dev/bin/onos-setup-karaf
index 84e9c94..5ff7279 100755
--- a/tools/dev/bin/onos-setup-karaf
+++ b/tools/dev/bin/onos-setup-karaf
@@ -17,7 +17,7 @@
 # Validates the specified IP regular expression against existing adapters.
 # Excludes local-loopback.
 function validateIp {
-    ifconfig | awk '{ print $2}' | grep -E -o "([0-9]{1,3}[\.]){3}[0-9]{1,3}" | grep $1
+    ifconfig | sed -ne 's:inet[^6][ adr:]*\([0-9.]*\).*:\1: p' | grep $1
 }
 
 # Parse optional arguments