GitSetup: Autofill the clone url with the last value

Makes it easier to fix typos

lib/screens/githostsetup_clone_url.dart

@@ -6,8 +6,12 @@ import 'githostsetup_button.dart';
 
 class GitCloneUrlPage extends StatefulWidget {
   final Function doneFunction;
+  final String initialValue;
 
-  GitCloneUrlPage({@required this.doneFunction});
+  GitCloneUrlPage({
+    @required this.doneFunction,
+    @required this.initialValue,
+  });
 
   @override
   GitCloneUrlPageState createState() {
@@ -61,6 +65,7 @@ class GitCloneUrlPageState extends State<GitCloneUrlPage> {
         focusNode: inputFormFocus,
         textInputAction: TextInputAction.done,
         onFieldSubmitted: (String _) => formSubmitted(),
+        initialValue: widget.initialValue,
       ),
     );
 
@@ -94,11 +99,13 @@ class GitCloneUrlKnownProviderPage extends StatefulWidget {
   final Function doneFunction;
   final Function launchCreateUrlPage;
   final GitHostType gitHostType;
+  final String initialValue;
 
   GitCloneUrlKnownProviderPage({
     @required this.doneFunction,
     @required this.launchCreateUrlPage,
     @required this.gitHostType,
+    @required this.initialValue,
   });
 
   @override
@@ -154,6 +161,7 @@ class GitCloneUrlKnownProviderPageState
         focusNode: inputFormFocus,
         textInputAction: TextInputAction.done,
         onFieldSubmitted: (String _) => formSubmitted(),
+        initialValue: widget.initialValue,
       ),
     );
 

lib/screens/githostsetup_screens.dart

@@ -79,15 +79,18 @@ class GitHostSetupScreenState extends State<GitHostSetupScreen> {
       assert(_pageChoice[0] != PageChoice0.Unknown);
 
       if (_pageChoice[0] == PageChoice0.CustomProvider) {
-        return GitCloneUrlPage(doneFunction: (String sshUrl) {
-          setState(() {
-            _gitCloneUrl = sshUrl;
+        return GitCloneUrlPage(
+          doneFunction: (String sshUrl) {
+            setState(() {
+              _gitCloneUrl = sshUrl;
 
-            _pageCount = pos + 2;
-            _nextPage();
-            _generateSshKey();
-          });
-        });
+              _pageCount = pos + 2;
+              _nextPage();
+              _generateSshKey();
+            });
+          },
+          initialValue: _gitCloneUrl,
+        );
       }
 
       return GitHostAutoConfigureChoicePage(
@@ -141,6 +144,7 @@ class GitHostSetupScreenState extends State<GitHostSetupScreen> {
           },
           launchCreateUrlPage: _launchCreateRepoPage,
           gitHostType: _gitHostType,
+          initialValue: _gitCloneUrl,
         );
       } else if (_pageChoice[1] == PageChoice1.Auto) {
         return GitHostSetupAutoConfigure(