Doc: the current Xcode version is always used

The "Xcode path" field is removed from iOS preferences
by the patch https://codereview.qt-project.org/67485.

Change-Id: I4608fe2b669f7e6e4ff106d957cc0238275465a9
Reviewed-by: Fawzi Mohamed <fawzi.mohamed@digia.com>

doc/src/ios/creator-ios-dev.qdoc

@@ -66,14 +66,14 @@
     can change the simulated hardware and software version from within iOS
     Simulator.
 
-    By default, \QC uses the Xcode version set as current on the Mac computer.
+    \QC uses the Xcode version set as current on the Mac computer.
     To check the version, enter the following command:
 
     \c {xcode-select --print-path}
 
-    To change the version, select \gui Preferences > \gui iOS, and select
-    another Xcode version in the \gui {Xcode path} field. This setting overrides
-    the version set by entering the \c {xcode-select --version} command.
+    To change the version, enter the following command:
+
+    \c {xcode-select --version}
 
     \section1 Configuring Devices