patch 8.1.0124: has('vcon') returns true even for non-win32 terminal

Problem:    has('vcon') returns true even for non-win32 terminal.
Solution:   Check the terminal type. (Nobuhiro Takasaki, closes #3106)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index cec6dab..ce45ad8 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -6609,7 +6609,7 @@
 #endif
 #ifdef FEAT_VTP
 	else if (STRICMP(name, "vcon") == 0)
-	    n = has_vtp_working();
+	    n = is_term_win32() && has_vtp_working();
 #endif
 #ifdef FEAT_NETBEANS_INTG
 	else if (STRICMP(name, "netbeans_enabled") == 0)
diff --git a/src/version.c b/src/version.c
index a2780f4..86e24fd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    124,
+/**/
     123,
 /**/
     122,