doc: Fix word order in developer-notes.md

This pull request fixes a word order error in developer-notes.md.

Before:

"In cases where do you call .c_str(), you might want to additionally check that the string does not contain embedded '\0' characters..."

After:

"In cases where you do call .c_str(), you might want to additionally check that the string does not contain embedded '\0' characters..."

Explanation:

The sentence had incorrect word order, making it grammatically incorrect. Rearranging "do you" to "you do" corrects the sentence, improving the readability and clarity of the documentation.

Author: secp512k2

doc/developer-notes.md

@@ -959,7 +959,7 @@ Strings and formatting
     - *Rationale*: Qt has built-in functionality for converting their string
       type from/to C++. No need to roll your own.
 
-  - In cases where do you call `.c_str()`, you might want to additionally check that the string does not contain embedded '\0' characters, because
+  - In cases where you do call `.c_str()`, you might want to additionally check that the string does not contain embedded '\0' characters, because
     it will (necessarily) truncate the string. This might be used to hide parts of the string from logging or to circumvent
     checks. If a use of strings is sensitive to this, take care to check the string for embedded NULL characters first
     and reject it if there are any (see `ParsePrechecks` in `strencodings.cpp` for an example).