Fix handling of templates data containing an equal sign

[BoboTiG]

• Wiktionary page: https://en.wiktionary.org/wiki/EPR%3DER

Wikicode:

{{alternative form of|mul|ER{{=}}EPR}}

Output:

<i>Alternative form of</i> <b></b>

Expected:

<i>Alternative form of</i> <b>ER=EPR</b>

[lasconic]

Maybe an idea, mimic the parameters module : https://en.wiktionary.org/wiki/Module:parameters