Fixed generated HTML for edge case chunk.


The HTML generated is incorrect when the diff chunk contained characters after the last pair of `@@`.

For example, given the diff:

```diff
@@ -23,11 +23,11 @@ OSFileEntry::OSFileEntry(const Polycode::String& fullPath, int type) {
   std::vector<String> parts = fullPath.split("/");

   if(parts.size() > 0) {
-    String path = parts[0];
+    String path = parts[0];  // this is line 26

     if(parts.size() > 1) {
       for(int i=1; i < parts.size()-1; i++) {
-        path += "/" + parts[i];
+        path += "/" + parts[i]; // this is line 30
       }
       init(path, parts[parts.size()-1], type);
     }
```

It would count the following as line 23:
```cpp
 OSFileEntry::OSFileEntry(const Polycode::String& fullPath, int type) {
````

But line 23 actually starts after the chunk's line. Regardless of code being on the same line as the diff chunk. So the correct line 23 is:
```cpp
std::vector<String> parts = fullPath.split("/");
```

This patch fixes this issue.