CYRUSONE LP and CYRUSONE FINANCE CORP. as Issuers, CYRUSONE INC. as Guarantor, and WELLS FARGO BANK, N.A. as Trustee 3.450% SENIOR NOTES DUE 2029 SECOND SUPPLEMENTAL INDENTURE Dated as of December 5, 2019 TO THE INDENTURE Dated as of December 5, 2019