Fix pod lib lint GoogleUtilities.podspec --use-libraries regression (#2130)

Author: paulb777

GoogleUtilities/CHANGELOG.md

@@ -1,4 +1,5 @@
 # Unreleased
+- Fix `pod lib lint GoogleUtilities.podspec --use-libraries` regression. (#2130)
 
 # 5.3.6
 - Fix nullability issues. (#2079)
@@ -11,7 +12,7 @@
 
 # 5.3.4
 - Fixed a crash caused by unprotected access to sessions in
-  `GULNetworkURLSession` (#1964).
+  `GULNetworkURLSession`. (#1964)
 
 # 5.3.3
 - Fixed an issue where GoogleUtilities would leak instances of `NSURLSession`.

GoogleUtilities/Network/GULNetworkURLSession.m

@@ -37,6 +37,9 @@ @implementation GULNetworkURLSession {
 #pragma clang diagnostic ignored "-Wunguarded-availability"
   /// The session configuration. NSURLSessionConfiguration' is only available on iOS 7.0 or newer.
   NSURLSessionConfiguration *_sessionConfig;
+
+  /// The current NSURLSession.
+  NSURLSession *__weak _Nullable _URLSession;
 #pragma clang diagnostic pop
 
   /// The path to the directory where all temporary files are stored before uploading.
@@ -50,9 +53,6 @@ @implementation GULNetworkURLSession {
 
   /// The current request.
   NSURLRequest *_request;
-
-  /// The current NSURLSession.
-  NSURLSession *__weak _Nullable _URLSession;
 }
 
 #pragma mark - Init