ProblemList-vthread.txt updated.

Author: lmesnik

test/hotspot/jtreg/ProblemList-vthread.txt

@@ -420,7 +420,6 @@ gc/arguments/TestMinInitialErgonomics.java
 gc/arguments/TestMaxRAMFlags.java
 gc/arguments/TestG1HeapSizeFlags.java
 gc/arguments/TestNewSizeThreadIncrease.java
-gc/g1/TestMixedGCLiveThreshold.java
 gc/g1/TestSkipRebuildRemsetPhase.java
 gc/g1/TestStringDeduplicationYoungGC.java
 gc/g1/TestStringDeduplicationTableRehash.java
@@ -431,6 +430,8 @@ gc/g1/TestStringDeduplicationAgeThreshold.java
 gc/g1/TestRemsetLoggingPerRegion.java
 gc/g1/TestRemsetLogging.java
 
+gc/g1/TestMixedGCLiveThreshold.java#25percent
+
 ####
 ## Expected exception is ignored