patch 8.1.2346: CTRL-R CTRL-R doesn't work with modifyOtherKeys

Problem:    CTRL-R CTRL-R doesn't work with modifyOtherKeys.
Solution:   Allow key codes when fetching argument for CTRL-R. (closes #5266)
            Also fix CTRL-G in Insert mode.
diff --git a/src/edit.c b/src/edit.c
index 1c168b6..c74f1bb 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -3906,6 +3906,7 @@
      * deleted when ESC is hit.
      */
     ++no_mapping;
+    ++allow_keys;
     regname = plain_vgetc();
     LANGMAP_ADJUST(regname, TRUE);
     if (regname == Ctrl_R || regname == Ctrl_O || regname == Ctrl_P)
@@ -3919,6 +3920,7 @@
 	LANGMAP_ADJUST(regname, TRUE);
     }
     --no_mapping;
+    --allow_keys;
 
 #ifdef FEAT_EVAL
     /* Don't call u_sync() while typing the expression or giving an error
@@ -4010,8 +4012,10 @@
      * deleted when ESC is hit.
      */
     ++no_mapping;
+    ++allow_keys;
     c = plain_vgetc();
     --no_mapping;
+    --allow_keys;
     switch (c)
     {
 	/* CTRL-G k and CTRL-G <Up>: cursor up to Insstart.col */