code_style: checking order while parsing header line

Although the position of this line of code will not affect the final result no matter where it is placed,
its position should still be adjusted for easier understanding.

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Commands/Diff.cs

@@ -145,9 +145,6 @@ private void ParseDiffHeaderLine(string line)
             if (line.StartsWith(SPECIAL_DIFF_START, StringComparison.Ordinal))
                 return;
 
-            if (line.StartsWith(SPECIAL_BINARY, StringComparison.Ordinal))
-                _result.IsBinary = true;
-
             if (ParseFileModeChange(line))
                 return;
 
@@ -159,6 +156,9 @@ private void ParseDiffHeaderLine(string line)
                 _result.NewHash = match.Groups[2].Value;
                 return;
             }
+
+            if (line.StartsWith(SPECIAL_BINARY, StringComparison.Ordinal))
+                _result.IsBinary = true;
         }
 
         private bool ParseChunkStartLine(string line)