🍏 remove redudant dependency (fix OS X compilation)

Author: skywinder

Sources/web3swift/Browser/BrowserViewController.swift

@@ -6,7 +6,6 @@
 //  Copyright © 2020 Matter Labs. All rights reserved.
 //
 
-import UIKit
 import WebKit
 
 open class BrowserViewController: UIViewController {

web3swift.podspec

@@ -8,7 +8,8 @@ Pod::Spec.new do |spec|
     spec.homepage     = 'https://github.com/matter-labs/web3swift'
     spec.author       = {"Alex Vlasov" => "[email protected]", "Anton Grigorev" => "[email protected]", "Petr Korolev" => "[email protected]"}
     spec.source       = { :git => 'https://github.com/matter-labs/web3swift.git', :tag => spec.version.to_s }
-    spec.source_files = "Sources/web3swift/{Contract,Convenience,EthereumABI,EthereumAddress,HookedFunctions,KeystoreManager,Promises,SwiftRLP,Transaction,Web3,Browser}/*.swift", "Sources/web3swift/{Tokens,Utils}/**/*.swift"
+    spec.source_files = "Sources/web3swift/{Contract,Convenience,EthereumABI,EthereumAddress,HookedFunctions,KeystoreManager,Promises,SwiftRLP,Transaction,Web3}/*.swift", "Sources/web3swift/{Tokens,Utils}/**/*.swift"
+    spec.ios.source_files   = 'Sources/web3swift/Browser/*.swift'
     spec.resource_bundle = { "Browser" => "Sources/web3swift/Browser/*.js" }
     spec.swift_version = '5.0'
     spec.frameworks = 'CoreImage'