Update the obsolete projects.kde.org URL

Use the generic redirect commits.kde.org.

Change discussed on the kde-frameworks-devel list:
https://mail.kde.org/pipermail/kde-frameworks-devel/2019-November/097564.html

CMakeLists.txt

@@ -5,7 +5,7 @@ project(KConfig VERSION ${KF5_VERSION})
 
 include(FeatureSummary)
 find_package(ECM 5.65.0  NO_MODULE)
-set_package_properties(ECM PROPERTIES TYPE REQUIRED DESCRIPTION "Extra CMake Modules." URL "https://projects.kde.org/projects/kdesupport/extra-cmake-modules")
+set_package_properties(ECM PROPERTIES TYPE REQUIRED DESCRIPTION "Extra CMake Modules." URL "https://commits.kde.org/extra-cmake-modules")
 feature_summary(WHAT REQUIRED_PACKAGES_NOT_FOUND FATAL_ON_MISSING_REQUIRED_PACKAGES)
 
 set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH})