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/ex_getln.c b/src/ex_getln.c
index 0a3d9d4..6832158 100644
--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -1747,6 +1747,7 @@
 #endif
 		putcmdline('"', TRUE);
 		++no_mapping;
+		++allow_keys;
 		i = c = plain_vgetc();	/* CTRL-R <char> */
 		if (i == Ctrl_O)
 		    i = Ctrl_R;		/* CTRL-R CTRL-O == CTRL-R CTRL-R */
@@ -1754,6 +1755,7 @@
 		    c = plain_vgetc();	/* CTRL-R CTRL-R <char> */
 		extra_char = NUL;
 		--no_mapping;
+		--allow_keys;
 #ifdef FEAT_EVAL
 		/*
 		 * Insert the result of an expression.