Tests: ExternalProject: Remove unnecessary 'svn --version' call

This test will fail to get a proper version number if running on a (e.g.
German) localized system because the regular expression used to match the
Subversion version output does not match. Instead of duplicating code just
remove the local test altogether and use the version that FindSubversion.cmake
already detects.

Tests/ExternalProject/CMakeLists.txt

@@ -343,13 +343,6 @@ endif()
 # Only do svn tests with svn >= version 1.2
 #
 if(do_svn_tests)
-  execute_process(COMMAND ${Subversion_SVN_EXECUTABLE} --version
-    OUTPUT_VARIABLE Subversion_VERSION_SVN
-    OUTPUT_STRIP_TRAILING_WHITESPACE)
-  string(REGEX REPLACE "^(.*\n)?svn, version ([.0-9]+).*"
-    "\\2" Subversion_VERSION_SVN "${Subversion_VERSION_SVN}")
-  message(STATUS "Subversion_VERSION_SVN='${Subversion_VERSION_SVN}'")
-
   if(Subversion_VERSION_SVN VERSION_LESS 1.2)
     message(STATUS "No ExternalProject svn tests with svn client less than version 1.2")
     set(do_svn_tests 0)