patch 8.1.2350: other text for CTRL-V in Insert mode with modifyOtherKeys

Problem:    Other text for CTRL-V in Insert mode with modifyOtherKeys.
Solution:   Convert the Escape sequence back to key as if modifyOtherKeys is
            not set, and use CTRL-SHIFT-V to get the Escape sequence itself.
            (closes #5254)
diff --git a/src/term.c b/src/term.c
index 83268c7..c7ac81c 100644
--- a/src/term.c
+++ b/src/term.c
@@ -4277,7 +4277,7 @@
 /*
  * Decode a modifier number as xterm provides it into MOD_MASK bits.
  */
-    static int
+    int
 decode_modifiers(int n)
 {
     int	    code = n - 1;