parser schema CHANGE always return non-const modules

Refs #1645
diff --git a/src/tree_schema.c b/src/tree_schema.c
index 702563a..86de5c4 100644
--- a/src/tree_schema.c
+++ b/src/tree_schema.c
@@ -1634,7 +1634,7 @@
 }
 
 API LY_ERR
-lys_parse(struct ly_ctx *ctx, struct ly_in *in, LYS_INFORMAT format, const char **features, const struct lys_module **module)
+lys_parse(struct ly_ctx *ctx, struct ly_in *in, LYS_INFORMAT format, const char **features, struct lys_module **module)
 {
     LY_ERR ret = LY_SUCCESS;
     struct lys_module *mod;
@@ -1678,7 +1678,7 @@
 }
 
 API LY_ERR
-lys_parse_mem(struct ly_ctx *ctx, const char *data, LYS_INFORMAT format, const struct lys_module **module)
+lys_parse_mem(struct ly_ctx *ctx, const char *data, LYS_INFORMAT format, struct lys_module **module)
 {
     LY_ERR ret;
     struct ly_in *in = NULL;
@@ -1694,7 +1694,7 @@
 }
 
 API LY_ERR
-lys_parse_fd(struct ly_ctx *ctx, int fd, LYS_INFORMAT format, const struct lys_module **module)
+lys_parse_fd(struct ly_ctx *ctx, int fd, LYS_INFORMAT format, struct lys_module **module)
 {
     LY_ERR ret;
     struct ly_in *in = NULL;
@@ -1710,7 +1710,7 @@
 }
 
 API LY_ERR
-lys_parse_path(struct ly_ctx *ctx, const char *path, LYS_INFORMAT format, const struct lys_module **module)
+lys_parse_path(struct ly_ctx *ctx, const char *path, LYS_INFORMAT format, struct lys_module **module)
 {
     LY_ERR ret;
     struct ly_in *in = NULL;