patch 8.2.4375: ctx_imports is not used

Problem:    ctx_imports is not used.
Solution:   Delete ctx_imports.  Add missing dependency.
diff --git a/src/userfunc.c b/src/userfunc.c
index 6007ab7..10a529e 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -1614,7 +1614,7 @@
 	    p = name + 2;
 	    len -= 2;
 	}
-	import = find_imported(p, len, FALSE, NULL);
+	import = find_imported(p, len, FALSE);
 
 	// imported function from another script
 	if (import != NULL)
@@ -4591,8 +4591,7 @@
 	{
 	    char_u *uname = untrans_function_name(name);
 
-	    import = find_imported(uname == NULL ? name : uname, 0,
-								  FALSE, NULL);
+	    import = find_imported(uname == NULL ? name : uname, 0, FALSE);
 	}
 
 	if (fp != NULL || import != NULL)