patch 8.2.4186: cannot use an import in 'patchexpr'

Problem:    Cannot use an import in 'patchexpr'.
Solution:   Set the script context when evaluating 'patchexpr'.  Do not
            require 'patchexpr' to return a bool, it was ignored anyway.
diff --git a/src/version.c b/src/version.c
index 9571473..8e659e0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4186,
+/**/
     4185,
 /**/
     4184,