Fix typo in funding statement (#425)

Corrected a typo in the contract number.

Author: fedorov

README.md

@@ -47,4 +47,4 @@ The developers gratefully acknowledge their support:
 * The [APOLLO Network](https://www.cancer.gov/about-nci/organization/cbiit/projects/apollo)
 
 This software is maintained in part by the [NCI Imaging Data Commons](https://imaging.datacommons.cancer.gov/) project,
-which has been funded in whole or in part with Federal funds from the National Cancer Institute, National Institutes of Health, Department of Health and Human Services, under task order no. HHSN26110071 under contract no. HHSN261201500003l. The statements do not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.
+which has been funded in whole or in part with Federal funds from the National Cancer Institute, National Institutes of Health, Department of Health and Human Services, under task order no. HHSN26110071 under contract no. HHSN261201500003I. The statements do not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.