Remove warning for running the compiler under Java 6/7

Now the compiler won't even start, so no need to check this manually.

compiler/tests-common/org/jetbrains/kotlin/integration/KotlinIntegrationTestBase.java

@@ -82,9 +82,6 @@ public abstract class KotlinIntegrationTestBase extends TestCaseWithTmpdir {
         content = normalizePath(content, getKotlinProjectHome(), "[KotlinProjectHome]");
         content = content.replaceAll(Pattern.quote(KotlinCompilerVersion.VERSION), "[KotlinVersion]");
         content = StringUtil.convertLineSeparators(content);
-        content = Pattern.compile("^.+running the Kotlin compiler under Java 6 or 7 is unsupported and will no longer be possible in a future update\\.\n", Pattern.MULTILINE)
-                .matcher(content)
-                .replaceAll("");
         return content;
     }