Correctly extract ORIOLEDB_PATCHSET_VERSION from git

 * Use patchset number is there is an exact match to the tag
 * Use commit hash otherwise

Author: akorotkov

configure

@@ -19559,7 +19559,7 @@ _ACEOF
 
 
 # Needed to check postgresql patches git tag during orioledb extension build
-ORIOLEDB_PATCHSET_VERSION=`git describe --tags | cut -d'_' -f2`
+ORIOLEDB_PATCHSET_VERSION=`tag=$(git describe --tags --exact-match 2>/dev/null) && echo "$tag" | cut -d'_' -f2 || git rev-parse HEAD`
 
 
 # If we are inserting PG_SYSROOT into CPPFLAGS, do so symbolically not

configure.ac

@@ -2426,7 +2426,7 @@ AC_DEFINE_UNQUOTED(PG_VERSION_NUM, $PG_VERSION_NUM, [PostgreSQL version as a num
 AC_SUBST(PG_VERSION_NUM)
 
 # Needed to check postgresql patches git tag during orioledb extension build
-[ORIOLEDB_PATCHSET_VERSION=`git describe --tags | cut -d'_' -f2`]
+[ORIOLEDB_PATCHSET_VERSION=`tag=$(git describe --tags --exact-match 2>/dev/null) && echo "$tag" | cut -d'_' -f2 || git rev-parse HEAD`]
 AC_SUBST(ORIOLEDB_PATCHSET_VERSION)
 
 # If we are inserting PG_SYSROOT into CPPFLAGS, do so symbolically not