Fix 24769 session id when multiple trackHubs session ids

htdocs/epdnew/gif/Arabidopsis_thaliana/AT4G18640_1.png

htdocs/ucsc/epdHub/dpu2/dpu2_viewer.txt

htdocs/ucsc/epdHub/dpu2_test/dpu2_viewer.txt

htdocs/ucsc/epdHub/epd_dpu2_viewer.txt

htdocs/ucsc_hubs/breastca/bc_hub_greb_esr1.txt

htdocs/ucsc_hubs/breastca/session_AIM2_STAT3_cage.txt

htdocs/ucsc_hubs/breastca/session_AIM2_STAT3_eu.txt

htdocs/ucsc_hubs/breastca/session_CCND1_ESR1_PGR_eu.txt

htdocs/ucsc_hubs/breastca/session_CCND1_eu.txt

htdocs/ucsc_hubs/breastca/session_CDH1_eu.txt

htdocs/ucsc_hubs/breastca/session_CDH1_eu_gallery.txt

htdocs/ucsc_hubs/breastca/session_CTSD_eu.txt

htdocs/ucsc_hubs/breastca/session_GREB1_ESR1_PGR_eu.txt

htdocs/ucsc_hubs/breastca/session_GREB1_eu.txt

...cs/ucsc_hubs/breastca/session_GREB1_eu_all_sel_tracks.txt

htdocs/ucsc_hubs/breastca/session_GREB1_eu_all_tracks.txt

...ucsc_hubs/breastca/session_GREB1_eu_all_tracks_Andrea.txt

htdocs/ucsc_hubs/breastca/session_JUN_eu.txt

htdocs/ucsc_hubs/breastca/session_KLK3_eu.txt

htdocs/ucsc_hubs/breastca/session_KLK3_eu_PB.txt