build; remove old options COSE_C_INCLUDE_SIGN0
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 54f94db..f004808 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -36,14 +36,8 @@
 option(COSE_C_INCLUDE_MAC "Include COSE_MAC" ON)
 option(COSE_C_INCLUDE_MAC0 "Include COSE_MAC0" ON)
 option(COSE_C_INCLUDE_SIGN "Include COSE_SIGN" ON)
-option(COSE_C_INCLUDE_SIGN0 "Include COSE_SIGN0" ON)
 option(COSE_C_INCLUDE_SIGN1 "Include COSE_SIGN1" ON)
 
-if(NOT COSE_C_INCLUDE_SIGN0)
-  message("Use COSE_C_INCLUDE_SIGN1 rather than COSE_C_INCLUDE_SIGN0")
-  set(COSE_C_INCLUDE_SIGN1 ${COSE_C_INCLUDE_SIGN0})
-endif()
-
 # Set the output of the libraries and executables.
 set(EXECUTABLE_OUTPUT_PATH ${PROJECT_BINARY_DIR}/bin)
 set(LIBRARY_OUTPUT_PATH ${PROJECT_BINARY_DIR}/lib)
@@ -266,7 +260,6 @@
 message(STATUS "COSE_C_INCLUDE_MAC:..............${COSE_C_INCLUDE_MAC}")
 message(STATUS "COSE_C_INCLUDE_MAC0:.............${COSE_C_INCLUDE_MAC0}")
 message(STATUS "COSE_C_INCLUDE_SIGN:.............${COSE_C_INCLUDE_SIGN}")
-message(STATUS "COSE_C_INCLUDE_SIGN0:............${COSE_C_INCLUDE_SIGN0}")
 message(STATUS "COSE_C_INCLUDE_SIGN1:............${COSE_C_INCLUDE_SIGN1}")
 message(STATUS "COSE_C_USE_CONTEXT:..............${COSE_C_USE_CONTEXT}")
 message(STATUS "COSE_C_FATAL_WARNINGS:...........${COSE_C_FATAL_WARNINGS}")