capitalise comment, makes it easier to read.

h2/src/main/org/h2/schema/Sequence.java

@@ -113,8 +113,8 @@ public class Sequence extends SchemaObjectBase {
      */
     public synchronized void flush(Session session) {
         if (session == null || !database.isSysTableLocked()) {
-            // this session may not lock the sys table (except if it already has locked it)
-            // because it must be committed immediately
+            // This session may not lock the sys table (except if it already has locked it)
+            // because it must be committed immediately,
             // otherwise other threads can not access the sys table.
             Session sysSession = database.getSystemSession();
             synchronized (sysSession) {