LIBJAVA_SRC_DIRS list doesn't need java/sql anymore

[Alan Bateman]

In CompileNativeLibraries.gmk then LIBJAVA_SRC_DIRS includes 
$(JDK_TOPDIR)/src/share/native/java/sql in the list but we have removed 
the final JDBC native method a few weeks back [1]. I think this means 
this directory can be removed from the list.

-Alan

[1] http://hg.openjdk.java.net/jdk8/jdk8/jdk/rev/8305ddc88a5a