Fix memory leak in eas_folder_get_message_sync()
Fix memory leak in eas_folder_get_message_sync()

==7221== 256 bytes in 2 blocks are definitely lost in loss record 26,636 of 31,050
==7221==    at 0x4A06582: realloc (vg_replace_malloc.c:525)
==7221==    by 0x3D330496CD: g_realloc (gmem.c:233)
==7221==    by 0x3D33062CF6: g_string_maybe_expand (gstring.c:401)
==7221==    by 0x3D330633B6: g_string_insert_len (gstring.c:741)
==7221==    by 0x3D3302F856: g_build_path_va (gfileutils.c:1488)
==7221==    by 0x3D33030F47: g_build_filename (gfileutils.c:1758)
==7221==    by 0x1E869976: eas_folder_get_message_sync (camel-eas-folder.c:204)
==7221==    by 0x64B370E: camel_folder_get_message_sync (camel-folder.c:3257)
==7221==    by 0x64B3BFD: folder_get_message_thread (camel-folder.c:1050)
==7221==    by 0x3D36C64B8B: run_in_thread (gsimpleasyncresult.c:838)
==7221==    by 0x3D36C56565: io_job_thread (gioscheduler.c:181)
==7221==    by 0x3D3306AA4F: g_thread_pool_thread_proxy (gthreadpool.c:319)

simo5/evolution-activesync,simo5/evolution-activesync,simo5/evolution-activesync