Remove extraneous line in .po reader, which caused it to disregard first line

Fixes #7337

(cherry picked from commit 474eafbbf68036251666cc1c4e86a82876b59e61)

core/io/translation_loader_po.cpp

@@ -33,8 +33,6 @@
 
 RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error, const String &p_path) {
 
-	String l = f->get_line();
-
 	enum Status {
 
 		STATUS_NONE,