Fix misleading intentation warning

[locallycompact]

This patch fixes this warning.

src/document.c: In function ‘char_link’:
src/document.c:1194:5: warning: this ‘else’ clause does not guard... [-Wmisleading-indentation]
     else nb_p--; i++;
     ^~~~
src/document.c:1194:18: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the ‘else’
     else nb_p--; i++;
                  ^

[fliiiix]

Any chance we can get this merged?