Don't add a page separator for a single page image (tesseract-ocr#3632)

This change was requested in issue tesseract-ocr#3628.

Author: amitdo

src/api/renderer.cpp

@@ -139,13 +139,13 @@ bool TessTextRenderer::AddImageHandler(TessBaseAPI *api) {
     return false;
   }
 
-  AppendString(utf8.get());
-
   const char *pageSeparator = api->GetStringVariable("page_separator");
-  if (pageSeparator != nullptr && *pageSeparator != '\0') {
+  if (pageSeparator != nullptr && *pageSeparator != '\0' && imagenum() > 0) {
     AppendString(pageSeparator);
   }
 
+  AppendString(utf8.get());
+
   return true;
 }