add HAVE_USLEEP=1 to fmdb/SQLCipher

for the warning in line 237 of FMDatabase.m:

 int requestedSleepInMillseconds = arc4random_uniform(50) + 50;
        int actualSleepInMilliseconds =
sqlite3_sleep(requestedSleepInMillseconds);
        if (actualSleepInMilliseconds != requestedSleepInMillseconds) {
            NSLog(@"WARNING: Requested sleep of %i milliseconds, but
SQLite returned %i. Maybe SQLite wasn't built with HAVE_USLEEP=1?",
requestedSleepInMillseconds, actualSleepInMilliseconds);
        }
        return 1;

FMDB.podspec

@@ -47,7 +47,7 @@ Pod::Spec.new do |s|
   s.subspec 'SQLCipher' do |ss|
     ss.dependency 'SQLCipher'
     ss.dependency 'FMDB/common'
-    ss.xcconfig = { 'OTHER_CFLAGS' => '$(inherited) -DSQLITE_HAS_CODEC' }
+    ss.xcconfig = { 'OTHER_CFLAGS' => '$(inherited) -DSQLITE_HAS_CODEC -DHAVE_USLEEP=1' }
   end
   
 end