Clean up after java/openjdk6 and java/openjdk6-jre removal

java/openjdk6 support was removed from Mk/bsd.java.mk (r512662) and
java/openjdk6 and java/openjdk6-jre were removed from the ports tree
(r512663).  Now this patch completely removes remaining stuff from the
ports tree.

PR:			241953 (exp-run)
Reviewed by:		glewis
Approved by:		portmgr (antoine)
Differential Revision:	https://reviews.freebsd.org/D22342

java/java3d/Makefile

@@ -21,7 +21,6 @@ USES=		gl tar:bzip2 xorg
 USE_JAVA=	yes
 USE_GL=		gl
 USE_XORG=	xt
-JAVA_VERSION=	1.6+
 JAVA_VENDOR=	openjdk
 USE_ANT=	yes
 LLD_UNSAFE=	yes