Enable mbedtls by default when building flexisip RPM.

configs/config-flexisip-rpm.cmake

@@ -51,6 +51,7 @@ set(LINPHONE_BUILDER_USE_SYSTEM_DEPENDENCIES YES CACHE BOOL "" FORCE)
 
 # Define default values for the flexisip builder options
 set(DEFAULT_VALUE_ENABLE_CXX_WRAPPER ON)
+set(DEFAULT_VALUE_ENABLE_MBEDTLS ON)
 set(DEFAULT_VALUE_ENABLE_REDIS ON)
 set(DEFAULT_VALUE_ENABLE_SOCI ON)
 set(DEFAULT_VALUE_ENABLE_UNIT_TESTS OFF)