feat(转换能力): 修复符号字体转换异常

ofdgo_pdf.go

@@ -81,6 +81,7 @@ type pdfImporter struct {
 	pageActionPage   int
 	fontIDs          map[*pdfgo.Font]string
 	fonts            map[*pdfgo.Font]*pdfImportedFont
+	symbolFonts      map[*pdfgo.Font]*pdfImportedFont
 	fontWarnings     map[string]bool
 	clipTexts        map[*pdfgo.TextClip][]TextObject
 	clipPaths        *renderCache[[32]byte, pdfClipPath]