disable license headers check for x-plugins, until we figure out what it should do

Original commit: elastic/x-pack-elasticsearch@48bc84865c

elasticsearch/license/build.gradle

@@ -3,5 +3,7 @@ subprojects {
     project.forbiddenPatterns {
       exclude '**/*.key'
     }
+    // someone figure out what the x-plugins logic should be
+    project.licenseHeaders.enabled = false
   }
 }

elasticsearch/qa/build.gradle

@@ -0,0 +1,6 @@
+subprojects {
+  project.afterEvaluate {
+    // someone figure out what the x-plugins logic should be
+    project.licenseHeaders.enabled = false
+  }
+}

elasticsearch/x-pack/build.gradle

@@ -150,3 +150,6 @@ thirdPartyAudit.excludes = [
     'com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator',
     'com.google.common.primitives.UnsignedBytes$LexicographicalComparatorHolder$UnsafeComparator$1',
 ]
+
+// someone figure out what the x-plugins logic should be
+licenseHeaders.enabled = false