Fixed warnings with MSVC compile.

FossilOrigin-Name: e0aa50c382a56bb02eaa589619b7e670006a26b3
diff --git a/src/trigger.c b/src/trigger.c
index 319f9bc..82acfbf 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -952,7 +952,7 @@
     ** invocation is disallowed if (a) the sub-program is really a trigger,
     ** not a foreign key action, and (b) the flag to enable recursive triggers
     ** is clear.  */
-    sqlite3VdbeChangeP5(v, p->zName && !(pParse->db->flags&SQLITE_RecTriggers));
+    sqlite3VdbeChangeP5(v, (u8)(p->zName && !(pParse->db->flags&SQLITE_RecTriggers)));
   }
 }