client session CHANGE use READ_TIMEOUT for internal get-schema reply wait

Fixes #43
diff --git a/src/config.h.in b/src/config.h.in
index 097c235..0179821 100644
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -50,7 +50,8 @@
 #define SCHEMAS_DIR "@CMAKE_INSTALL_PREFIX@/@DATA_INSTALL_DIR@"
 
 /*
- * Partial message read timeout in seconds (also used as nc_pollsession lock timeout)
+ * Partial message read timeout in seconds
+ * (also used as nc_pollsession lock timeout and internal <get-schema> RPC reply timeout)
  */
 #define NC_READ_TIMEOUT @READ_TIMEOUT@