decode/erspan: Add warning ERSPAN Type I config

This commit adds a warning value when ERSPAN Type I configuration
settings are detected; specifically, when ERSPAN Type I `enabled` is
specified.

Enabling/disabling ERSPAN Type I decode has been deprecated in 6.x

src/util-error.c

@@ -369,6 +369,7 @@ const char * SCErrorToString(SCError err)
         CASE_CODE (SC_WARN_ALERT_CONFIG);
         CASE_CODE (SC_WARN_REGISTRATION_FAILED);
         CASE_CODE (SC_ERR_ERF_BAD_RLEN);
+        CASE_CODE (SC_WARN_ERSPAN_CONFIG);
 
         CASE_CODE (SC_ERR_MAX);
     }

src/util-error.h

@@ -359,6 +359,7 @@ typedef enum {
     SC_WARN_PCRE_JITSTACK,
     SC_WARN_REGISTRATION_FAILED,
     SC_ERR_ERF_BAD_RLEN,
+    SC_WARN_ERSPAN_CONFIG,
 
     SC_ERR_MAX
 } SCError;