Delete duplicate recording rules before adding unique index.

Commit af5836e added a unique index to the record table to prevent
the creation of duplicate recording rules, primarly from the internal
web interface or mythweb.  However, some users had already created
duplicate rules which caused the index creation to fail.  This commit
changes the update to delete the duplicate rules before creating the
index.

Author: gigem

mythtv/libs/libmythtv/dbcheck.cpp

@@ -2728,6 +2728,13 @@ NULL
     if (dbver == "1327")
     {
         const char *updates[] = {
+            "DELETE r1 FROM record r1, record r2 "
+            "  WHERE r1.chanid = r2.chanid AND "
+            "        r1.starttime = r2.starttime AND "
+            "        r1.startdate = r2.startdate AND "
+            "        r1.title = r2.title AND "
+            "        r1.type = r2.type AND "
+            "        r1.recordid > r2.recordid",
             "ALTER TABLE record DROP INDEX chanid",
             "ALTER TABLE record ADD UNIQUE INDEX "
             " (chanid, starttime, startdate, title, type)",