Disable memory buffer allocator in full config

This commit modifies `config.pl` to not set MBEDTLS_MEMORY_BUFFER_ALLOC
with the `full` option.
diff --git a/scripts/config.pl b/scripts/config.pl
index 42ec6f8..c81cb92 100755
--- a/scripts/config.pl
+++ b/scripts/config.pl
@@ -26,6 +26,8 @@
 #   MBEDTLS_ECP_DP_M221_ENABLED
 #   MBEDTLS_ECP_DP_M383_ENABLED
 #   MBEDTLS_ECP_DP_M511_ENABLED
+#   MBEDTLS_MEMORY_BACKTRACE
+#   MBEDTLS_MEMORY_BUFFER_ALLOC_C
 #   MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES
 #   MBEDTLS_NO_PLATFORM_ENTROPY
 #   MBEDTLS_REMOVE_ARC4_CIPHERSUITES
@@ -86,6 +88,8 @@
 MBEDTLS_ECP_DP_M221_ENABLED
 MBEDTLS_ECP_DP_M383_ENABLED
 MBEDTLS_ECP_DP_M511_ENABLED
+MBEDTLS_MEMORY_BACKTRACE
+MBEDTLS_MEMORY_BUFFER_ALLOC_C
 MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES
 MBEDTLS_NO_PLATFORM_ENTROPY
 MBEDTLS_RSA_NO_CRT