Deprecated: Methods with the same name as their class will not be constructors

On one of my sites I’ve been using Online Backup for WordPress without issues for years. Just updated it yesterday and now this text is appearing at the top of all pages of the site:

Deprecated: Methods with the same name as their class will not be constructors in a future version of PHP; WPOnlineBackup has a deprecated constructor in /hermes/bosnaweb17a/b90/ipg.themarketingquizcom/pmcsconsulting/dev/wp-content/plugins/wponlinebackup/wponlinebackup.php on line 91

So I went to the site’s admin area, clicked Online Backup and then Help & Support. In the white box it says:
Deprecated: Non-static method WPOnlineBackup_Formatting::Fix_B() should not be called statically in /hermes/bosnaweb17a/b90/ipg.themarketingquizcom/pmcsconsulting/dev/wp-content/plugins/wponlinebackup/include/admin.php on line 274 Deprecated: Non-static method WPOnlineBackup_Formatting::Fix_B() should not be called statically in /hermes/bosnaweb17a/b90/ipg.themarketingquizcom/pmcsconsulting/dev/wp-content/plugins/wponlinebackup/include/admin.php on line 245 Deprecated: Non-static method WPOnlineBackup_Formatting::Fix_B() should not be called statically in /hermes/bosnaweb17a/b90/ipg.themarketingquizcom/pmcsconsulting/dev/wp-content/plugins/wponlinebackup/include/admin.php on line 262 Deprecated: Non-static method WPOnlineBackup_Formatting::Fix_B() should not be called statically in /hermes/bosnaweb17a/b90/ipg.themarketingquizcom/pmcsconsulting/dev/wp-content/plugins/wponlinebackup/include/admin.php on line 262 Deprecated: Non-static method WPOnlineBackup_Formatting::Fix_B() should not be called statically in /hermes/bosnaweb17a/b90/ipg.themarketingquizcom/pmcsconsulting/dev/wp-content/plugins/wponlinebackup/include/admin.php on line 262

And under “The following anonymous information . . .” it says:

Online Backup for WordPress Plugin Version 3.0.4
WordPress Version: 4.8.2 (standalone)
PHP Version: 7.1.1
Server Software: Apache/2
MySQL Server Version: (unknown)
MySQL Client Version: ; MySQL Packet Size: 32?MiB
Memory: 712M; Post: 20M; Upload: 20M; Timeout: 120
Memory Changable: Yes; Admin Cache Size: 128.69?KiB
Status: 1 row, 18.31?KiB packet size, 114.47?KiB cache freed, 22.68?MiB memory used
Capabilities: hashcopy gzdeflate php5hash DES AES128 AES192 AES256
End of Information

I have searched this forum for a post that might address this issue, but I am getting no results. Please advise what I should do to clear up this error/issue, so I don’t have to replace Online Backup for WordPress with a different backup plugin.

The page I need help with: [log in to see the link]