RFR: 8211860: Avoid reading security properties eagerly on Manifest class initialization

[Claes Redestad]

Hi,

JDK-8207768 cause a noticeable regression in a subset of our startup 
tests due eagerly loading security.properties for getting a property 
that's only used in exceptional circumstances. Ensuring Manifest doesn't 
eagerly read in the property value in the static initializer avoids this.

Webrev: http://cr.openjdk.java.net/~redestad/8211860/jdk.00/
Bug: https://bugs.openjdk.java.net/browse/JDK-8211860

Thanks!

/Claes