Changed the value of a loop var to match accessing an array, ultimately to make the compiler be quiet.

src/fmdb/FMDatabase.m

@@ -116,7 +116,7 @@ + (SInt32)FMDBVersion {
         }
 
         NSArray *components = [prodVersion componentsSeparatedByString:@"."];
-        for (NSInteger i = 0; i < 3; i++) {
+        for (NSUInteger i = 0; i < 3; i++) {
             SInt32 component = [components[i] intValue];
             if (component > 15) {
                 NSLog(@"FMDBVersion is invalid: Please use FMDBUserVersion instead.");