fix: correct DT5 patch applyto from 'T' to 'DT' in PATCHES.xml

pdb2pqr/dat/PATCHES.xml

@@ -579,7 +579,7 @@ OF THE POSSIBILITY OF SUCH DAMAGE.
   </patch>
   <patch>
      <name>DT5</name>
-     <applyto>T</applyto>
+     <applyto>DT</applyto>
      <remove>O1P</remove>
      <remove>P</remove>
      <remove>O2P</remove>

tests/patches_test.py

@@ -0,0 +1,20 @@
+from pathlib import Path
+
+from pdb2pqr.definitions import Definition
+
+
+def test_dt5_patch_applies_to_dt_reference() -> None:
+    dat_dir = Path(__file__).resolve().parents[1] / "pdb2pqr" / "dat"
+
+    with (
+        (dat_dir / "AA.xml").open() as aa_file,
+        (dat_dir / "NA.xml").open() as na_file,
+        (dat_dir / "PATCHES.xml").open() as patch_file,
+    ):
+        definition = Definition(aa_file, na_file, patch_file)
+
+    assert "DT" in definition.map
+    assert "DT5" in definition.map
+    assert "P" not in definition.map["DT5"].map
+    assert "O1P" not in definition.map["DT5"].map
+    assert "H5T" in definition.map["DT5"].map