common: Fix translations in --help for gpgrt < 1.47

* common/mapstrings.c (map_static_macro_string): Add hack.
--

common/mapstrings.c

@@ -154,6 +154,14 @@ map_static_macro_string (const char *string)
   membuf_t mb;
   char *p;
 
+  /* We use a hack if we don't use the fixed gpgrt 1.47
+   * (commit 885a287a57cf060b4c5b441822c09d23b8dee2bd) */
+#if GPGRT_VERSION_NUMBER < 0x012f00
+  if (string && !strncmp (string, "Project-Id-Version:", 19)
+      && strstr (string, "PO-Revision-Date:"))
+    return "";
+#endif
+
   if ((s = already_mapped (string)))
     return s;
   s = string;