Remove explicit AppScheduledExecutorService shutdown (commit revert)

Revert "Problem: manually shutdown AppScheduledExecutorService to allow compiler stop properly"

The commit was added during update to 162.1024.1 to fix hangs in ant
tasks on teamcity because of some thread created in
AppScheduledExecutorService service.

Remove the commit because can't reproduce those hangs under 162.2946
(Probably https://github.com/JetBrains/intellij-community/commit/12a079ef41882343bf83ef2a7dcee820b55fd154 fixed the hangs).

This should also be addressed in fix for https://youtrack.jetbrains.com/issue/IDEA-169562

This reverts commit 99a75021e1.

compiler/conditional-preprocessor/src/org.jetbrains.kotlin.preprocessor/PreprocessorCLI.kt

@@ -16,9 +16,9 @@
 @file:JvmName("PreprocessorCLI")
 package org.jetbrains.kotlin.preprocessor
 
-import com.intellij.util.concurrency.AppExecutorUtil
-import com.intellij.util.concurrency.AppScheduledExecutorService
 import java.io.File
+import java.util.concurrent.Executors
+import java.util.concurrent.TimeUnit
 
 fun main(args: Array<String>) {
     if (args.size != 3) {
@@ -32,12 +32,5 @@ fun main(args: Array<String>) {
     val profile = createProfile(args[2], targetPath)
 
     println("Preprocessing sources in $sourcePath to $targetPath with profile ${profile.name}")
-
-    try {
-        Preprocessor().processSources(sourcePath, profile)
-    }
-    finally {
-        val service = AppExecutorUtil.getAppScheduledExecutorService() as AppScheduledExecutorService
-        service.shutdownAppScheduledExecutorService()
-    }
+    Preprocessor().processSources(sourcePath, profile)
 }