yet another funny ETRS89 spelling

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@49032 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/proj/convert.c

@@ -736,6 +736,8 @@ static const char *papszDatumEquiv[] = {
     "European_Terrestrial_Reference_System_1989",
     "ETRS_1989",
     "European_Terrestrial_Reference_System_1989",
+    "ETRS89",
+    "European_Terrestrial_Reference_System_1989",
     "ETRF_1989",
     "European_Terrestrial_Reference_System_1989",
     "NZGD_2000",