Pornind de la ce ai acolo, incearca asta:

Cod:
# Redirect www to non-www https
RewriteCond %{HTTP_HOST} ^www\.pctroubleshooting\.ro$ [NC]
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteRule ^(.*)$ https://pctroubleshooting.ro/$1 [R=301,L]
RewriteCond %{HTTPS} off
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
Am ingrosat ce am adaugat la ceea ce deja ai.
Cu precautie ca nu e testat.
Sau poti incerca metoda mai eleganta:

Cod:
RewriteEngine On
RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} ^www\. [NC]
RewriteCond %{HTTP_HOST} ^(?:www\.)?(.+)$ [NC]
RewriteCond %{REQUEST_URI} !^/[0-9]+\..+\.cpaneldcv$
RewriteCond %{REQUEST_URI} !^/[A-F0-9]{32}\.txt(?:\ Comodo\ DCV)?$
RewriteRule ^ https://%1%{REQUEST_URI} [L,NE,R=301]
Repet, fii precaut, sunt obosit la ora la care scriu...