Revert "Fix error when using the message operator with regex on ..."

Revert submission 356100

Reason for revert:

Breaks submit requirements because SRs use change index predicates
and evaluate them locally. So they don't depend on the index version.
The method-based check that we bring back here is overriden in the
SR subclass of ChangQueryBuilder to model that.

Reverted changes: /q/submissionid:356100

Release-Notes: skip
Change-Id: I4e551ac532788b419f58492bc2b5d8d0784d7892

java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java

diff --git a/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java b/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java
index da75057..510ca01 100644
--- a/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java
+++ b/java/com/google/gerrit/server/query/change/ChangeQueryBuilder.java
@@ -1141,10 +1141,7 @@
   @Operator
   public Predicate<ChangeData> message(String text) throws QueryParseException {
     if (text.startsWith("^")) {
-      if (!args.index.getSchema().hasField(ChangeField.COMMIT_MESSAGE_EXACT)) {
-        throw new QueryParseException(
-            "'message' operator with regular expression is not supported on this gerrit host");
-      }
+      checkFieldAvailable(ChangeField.COMMIT_MESSAGE_EXACT, "messageexact");
       return new RegexMessagePredicate(text);
     }
     return ChangePredicates.message(text);