cmake: drop unset `SHA1_TYPE`

We never set `SHA1_TYPE` to `builtin`.  Don't bother testing for it.

CMakeLists.txt

@@ -296,12 +296,12 @@ ENDIF()
 IF (USE_SHA1DC)
 	ADD_DEFINITIONS(-DGIT_SHA1_COLLISIONDETECT)
 	FILE(GLOB SRC_SHA1 src/hash/hash_collisiondetect.c src/hash/sha1dc/*)
-ELSEIF (WIN32 AND NOT MINGW AND NOT SHA1_TYPE STREQUAL "builtin")
+ELSEIF (WIN32 AND NOT MINGW)
 	ADD_DEFINITIONS(-DGIT_SHA1_WIN32)
 	FILE(GLOB SRC_SHA1 src/hash/hash_win32.c)
 ELSEIF (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
 	ADD_DEFINITIONS(-DGIT_SHA1_COMMON_CRYPTO)
-ELSEIF (OPENSSL_FOUND AND NOT SHA1_TYPE STREQUAL "builtin")
+ELSEIF (OPENSSL_FOUND)
 	ADD_DEFINITIONS(-DGIT_SHA1_OPENSSL)
 	IF (CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
 		LIST(APPEND LIBGIT2_PC_LIBS "-lssl")