[FLINK-35420][hadoop-compatibility][test] Workaround some strange scala compilation issue

Without this fix a couple of people did experience compilation error in the IntelliJ:

WordCountMapredITCase.scala:42:8
value isFalse is not a member of ?0
possible cause: maybe a semicolon is missing before `value isFalse'?
      .isFalse()

Author: pnowojski

flink-connectors/flink-hadoop-compatibility/src/test/scala/org/apache/flink/api/hadoopcompatibility/scala/WordCountMapredITCase.scala

@@ -38,7 +38,6 @@ class WordCountMapredITCase extends JavaProgramTestBase {
   def checkOperatingSystem() {
     // FLINK-5164 - see https://wiki.apache.org/hadoop/WindowsProblems
     assumeThat(OperatingSystem.isWindows)
-      .as("This test can't run successfully on Windows.")
       .isFalse()
   }
 

flink-connectors/flink-hadoop-compatibility/src/test/scala/org/apache/flink/api/hadoopcompatibility/scala/WordCountMapreduceITCase.scala

@@ -40,7 +40,6 @@ class WordCountMapreduceITCase extends JavaProgramTestBase {
   def checkOperatingSystem() {
     // FLINK-5164 - see https://wiki.apache.org/hadoop/WindowsProblems
     assumeThat(OperatingSystem.isWindows)
-      .as("This test can't run successfully on Windows.")
       .isFalse()
   }