RFR: 8149886: 16 windows tests broke with recent putback

[Jonathan Gibbons]

Please review the following quick fix for a latent bug in javadoc, 
uncovered by recent change to use the nio.file API.

The root cause is that you typically cannot create a Path from a string 
containing a URL; you may get an exception -- and will get one on 
Windows trying to create a Path for a string beginning http:....

The fix is to reverse two tests to ensure the string is not a URL

JBS: https://bugs.openjdk.java.net/browse/JDK-8149886
Webrev: http://cr.openjdk.java.net/~jjg/8149886/webrev.00

-- Jon