patch 8.2.2056: configure fails when building with implicit-function-declaration

Problem:    Configure fails when building with the
            "implicit-function-declaration" error enabled, specifically on Mac.
Solution:   Declear the functions like in the source code. (suggestion by
            Clemens Lang, closes #7380)
diff --git a/src/version.c b/src/version.c
index 8c4c3fa..0308c91 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2056,
+/**/
     2055,
 /**/
     2054,