DOC: Non-permanent github link detected

pre-commit hook id: check-vcs-permalinks

Non-permanent github link detected.

Whet to non-permanent link on github, and
press [y] to load a permalink. Replaced
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CMake/ITKSetStandardCompilerFlags.cmake

@@ -229,7 +229,7 @@ function(check_avx_flags avx_flags_var)
 endfunction()
 
 # Check for the presence of SSE2.
-# Adapted from the AVX check and https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/ThirdParty/VNL/src/vxl/config/cmake/config/vxl_platform_tests.cxx#L164-L178
+# Adapted from the AVX check and https://github.com/InsightSoftwareConsortium/ITK/blob/4cbe24cb4a45d689cadd56d554b8ccf3584a5ca6/Modules/ThirdParty/VNL/src/vxl/config/cmake/config/vxl_platform_tests.cxx#L164-L178
 function(check_sse2_flags sse2_flags_var)
 
   # set flags to be used in check_cxx_source_runs below