patch 8.1.0104: can't build without the +eval feature

Problem:    Can't build without the +eval feature.
Solution:   Add #ifdef.
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 5a69c81..b095b95 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -5693,7 +5693,11 @@
 	nextlist->has_pim = FALSE;
 	++nfa_listid;
 	if (prog->re_engine == AUTOMATIC_ENGINE
-		&& (nfa_listid >= NFA_MAX_STATES || nfa_fail_for_testing))
+		&& (nfa_listid >= NFA_MAX_STATES
+# ifdef FEAT_EVAL
+		    || nfa_fail_for_testing
+# endif
+		    ))
 	{
 	    /* too many states, retry with old engine */
 	    nfa_match = NFA_TOO_EXPENSIVE;
diff --git a/src/version.c b/src/version.c
index 45f339b..e2ccc11 100644
--- a/src/version.c
+++ b/src/version.c
@@ -779,6 +779,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    104,
+/**/
     103,
 /**/
     102,