Remove unused string helper

common/string_utils.cpp

@@ -1122,15 +1122,4 @@ std::string Double2Str( double aValue )
     }
 
     return std::string( buf, len );
-}
-
-
-wxString AngleToStringDegrees( double aAngle )
-{
-    wxString text;
-
-    text.Printf( wxT( "%.3f" ), aAngle / 10.0 );
-    StripTrailingZeros( text, 1 );
-
-    return text;
-}
+}