[NFC] Fix Z3 version detection regexp in llvm/cmake/modules/FindZ3.cmake

[steakhal]

Summary

We use the major.minor.build version format in this file, except when we try to parse the result of the test binary.
In that regular expression, we expect the major.minor.build.rev format, which is never fulfilled.

[NoQ]

I've no idea what any of this does but whatever works, thanks!

llvm/cmake/modules/FindZ3.cmake

try_run(
     ${CMAKE_BINARY_DIR}
     ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeTmp/testz3.c
     COMPILE_DEFINITIONS -I"${z3_include}"
     LINK_LIBRARIES -L${z3_lib_path} -lz3
     RUN_OUTPUT_VARIABLE SRC_OUTPUT
   )
 
   if(Z3_COMPILED)
-    string(REGEX REPLACE "([0-9]*\\.[0-9]*\\.[0-9]*\\.[0-9]*)" "\\1"
+    string(REGEX REPLACE "([0-9]*\\.[0-9]*\\.[0-9]*)" "\\1"
            z3_version "${SRC_OUTPUT}")
     set(Z3_VERSION_STRING ${z3_version} PARENT_SCOPE)
   endif()
 endfunction(check_z3_version)
 
 # Looking for Z3 in LLVM_Z3_INSTALL_DIR
 find_path(Z3_INCLUDE_DIR NAMES z3.h
   NO_DEFAULT_PATH