Bump com.microsoft.azure:msal4j in /mail-ms-exchange-oauth2 (#131)

Bumps [com.microsoft.azure:msal4j](https://github.com/AzureAD/microsoft-authentication-library-for-java) from 1.13.2 to 1.15.1.
- [Release notes](https://github.com/AzureAD/microsoft-authentication-library-for-java/releases)
- [Changelog](https://github.com/AzureAD/microsoft-authentication-library-for-java/blob/dev/changelog.txt)
- [Commits](AzureAD/microsoft-authentication-library-for-java@v1.13.2...v1.15.1)

---
updated-dependencies:
- dependency-name: com.microsoft.azure:msal4j
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

mail-ms-exchange-oauth2/pom.xml

@@ -18,7 +18,7 @@
         with IMAP protocol and access email data for Office 365 users using OAuth2 authentication</description>
 
     <properties>
-        <msal4j-version>1.13.2</msal4j-version>
+        <msal4j-version>1.15.1</msal4j-version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <category>Mail</category>
     </properties>