warn instead of fatal error when proxy configs are erroneous

when an error is returned from NewProxyConfig because of wrong
proxy env variables or missing proxy ca cert file, in root.go it
was fatal error which prevented running of any crc commands  and
user was not able to unset the invalid config

this changes it to be a warning, which will allow users to correct
the wrong config

this fixes #3690 #3098

cmd/crc/cmd/root.go

@@ -56,7 +56,7 @@ func init() {
 	}
 
 	if err := setProxyDefaults(); err != nil {
-		logging.Fatal(err.Error())
+		logging.Warn(err.Error())
 	}
 
 	// Initiate segment client