Update cheatsheet.fr.md

12.temporary_ins/20.magnetostatics-vacuum/40.ampere-theorem-applications/30.cylindrical-current-distributions/20.solenoidal-current/10.ampere-integral/20.overview/cheatsheet.fr.md

@@ -249,7 +249,7 @@ $`\Longrightarrow\quad\overrightarrow{dl} \cdot \overrightarrow{B}=0`$
  <br>
  $`\displaystyle\quad\quad\quad\quad = \Big[ B_z(\rho_{DA})\times z\Big]_{z_0}^{z_0+h}`$   
  <br>
- $`$`\footnotesize{\color{blue}{M\in [DA]\;\Longrightarrow \;\rho_{DA}=\rho_M`}}$  
+ $`$`\footnotesize{\color{blue}{M\in [DA]\;\Longrightarrow \;\rho_{DA}=\rho_M`}}}$  
  <br>
  **$`\displaystyle\quad\quad\quad\quad = h\; B_z(\rho_M)`$**