Documenting 'implicit omit' fix (issue #588)

Signed-off-by: Adam Knapp <adam.knapp@ericsson.com>

usrguide/referenceguide/2-ttcn-3_limitations_in_this_version.adoc

@@ -49,7 +49,6 @@ function f_check() return boolean {
 * The language specification, after the "language" keyword, is ignored by the compiler.
 * For record of/set of types of fixed size, which have a length restriction of one concrete value, and arrays the `sizeof()` and `lengthof()` predefined functions are not standard compliant: `sizeof()` returns the number of elements, `lengthof()` returns the index of the last initialized element plus one.
 * IPv6 networking between the MC, HC and Parallel Test Components is supported only on Linux and Cygwin 1.7.
-* The `optional "implicit omit"` attribute is not applied recursively.
 * The `optional "implicit omit"` attribute can be applied directly to global value and template definitions, but not to local value and template definitions.
 * The `optional "implicit omit"` attribute can be applied to a module, in which case it will have effect on global value and template definitions in the module,
 and local value and template definitions in the module, with the exception of (local) variable definitions