patch 8.1.1117: build failure without the +eval feature

Problem:    Build failure without the +eval feature.
Solution:   Add #ifdef.
diff --git a/src/ex_cmds2.c b/src/ex_cmds2.c
index 97bf143..31caa93 100644
--- a/src/ex_cmds2.c
+++ b/src/ex_cmds2.c
@@ -5115,6 +5115,7 @@
     void
 ex_scriptversion(exarg_T *eap UNUSED)
 {
+#ifdef FEAT_EVAL
     int		nr;
 
     if (!getline_equal(eap->getline, eap->cookie, getsourceline))
@@ -5130,6 +5131,7 @@
 	semsg(_("E999: scriptversion not supported: %d"), nr);
     else
 	current_sctx.sc_version = nr;
+#endif
 }
 
 #if defined(FEAT_EVAL) || defined(PROTO)