Remove unused definitions of WEBKIT_VERSION_MIN_REQUIRED

Remove unused definitions of WEBKIT_VERSION_MIN_REQUIRED
https://bugs.webkit.org/show_bug.cgi?id=145345

Reviewed by Sam Weinig.

Source/bmalloc:

* Configurations/Base.xcconfig: Also changed to use $(inherited).

Source/JavaScriptCore:

* Configurations/Base.xcconfig: Also changed to use $(inherited).

Source/WebCore:

* Configurations/WebCore.xcconfig: Also changed to use $(inherited).

Source/WebInspectorUI:

* Configurations/Base.xcconfig:

Source/WebKit/mac:

* Configurations/WebKitLegacy.xcconfig: Also changed to use $(inherited).

Source/WTF:

* Configurations/Base.xcconfig: Also changed to use $(inherited).

Tools:

* DumpRenderTree/mac/Configurations/Base.xcconfig:
* LayoutTestRelay/Configurations/Base.xcconfig:
* TestWebKitAPI/Configurations/Base.xcconfig:
* WebKitTestRunner/Configurations/Base.xcconfig:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@184845 268f45cc-cd09-0410-ab3c-d52691b4dbfc