Remove '\n' line separator from "Test starting"/"Test finished" defined in i18n.properties

Currently the output produced by jtharness in harness.trace log file looks like:
====================
Test starting: api/java_lang/annotation/Annotation/index.html#Annotation

Test starting: api/java_lang/AbstractMethodError/serial/index.html#ConstructorTests

Test starting: api/java_lang/AbstractMethodError/serial/index.html#InputTests

Test starting: api/java_lang/AbstractMethodError/index.html#Ctor

Test finished: api/java_lang/AbstractMethodError/index.html#Ctor: Passed. test cases: 2; all passed
====================

"Test starting"/"Test finished" are defined starting with "\n" for some unclear reason in `i18n.properties` file:
http://hg.openjdk.java.net/code-tools/jtharness/file/f372b553b541/src/com/sun/javatest/i18n.properties#l365

This is to remove "\n" from 'trace.testStarting'\'trace.testFinished' props values