C++: Update security-severity tags.

Author: geoffw0

cpp/ql/src/Likely Bugs/Protocols/TlsSettingsMisconfiguration.ql

@@ -3,6 +3,7 @@
  * @description Using the TLS or SSLv23 protocol from the boost::asio library, but not disabling deprecated protocols, or disabling minimum-recommended protocols.
  * @kind problem
  * @problem.severity error
+ * @security-severity 7.5
  * @id cpp/boost/tls-settings-misconfiguration
  * @tags security
  *       external/cwe/cwe-326

cpp/ql/src/Likely Bugs/Protocols/UseOfDeprecatedHardcodedProtocol.ql

@@ -3,6 +3,7 @@
  * @description Using a deprecated hard-coded protocol using the boost::asio library.
  * @kind problem
  * @problem.severity error
+ * @security-severity 7.5
  * @id cpp/boost/use-of-deprecated-hardcoded-security-protocol
  * @tags security
  *       external/cwe/cwe-327