patch 8.1.2171: mouse support not always available

Problem:    Mouse support not always available.
Solution:   Enable mouse support also in tiny version.  Do not define
            FEAT_MOUSE_XTERM on MS-Windows (didn't really work).
diff --git a/src/version.c b/src/version.c
index b7d9cb7..0dd3677 100644
--- a/src/version.c
+++ b/src/version.c
@@ -359,15 +359,11 @@
 	"-mksession",
 #endif
 	"+modify_fname",
-#ifdef FEAT_MOUSE
 	"+mouse",
-#  ifdef FEAT_MOUSESHAPE
+#ifdef FEAT_MOUSESHAPE
 	"+mouseshape",
-#  else
+#else
 	"-mouseshape",
-#  endif
-# else
-	"-mouse",
 #endif
 
 #if defined(UNIX) || defined(VMS)
@@ -402,11 +398,7 @@
 #endif
 
 #if defined(UNIX) || defined(VMS)
-# ifdef FEAT_MOUSE_XTERM
 	"+mouse_sgr",
-# else
-	"-mouse_sgr",
-# endif
 # ifdef FEAT_SYSMOUSE
 	"+mouse_sysmouse",
 # else
@@ -417,11 +409,7 @@
 # else
 	"-mouse_urxvt",
 # endif
-# ifdef FEAT_MOUSE_XTERM
 	"+mouse_xterm",
-# else
-	"-mouse_xterm",
-# endif
 #endif
 
 #ifdef FEAT_MBYTE_IME
@@ -754,6 +742,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2171,
+/**/
     2170,
 /**/
     2169,