[stacktrace.basic.nonmem] Fix indentation

Author: Andreas-Krug

source/diagnostics.tex

@@ -2289,8 +2289,8 @@
 \indexlibrarymember{swap}{basic_stacktrace}%
 \begin{itemdecl}
 template<class Allocator>
-void swap(basic_stacktrace<Allocator>& a, basic_stacktrace<Allocator>& b)
-  noexcept(noexcept(a.swap(b)));
+  void swap(basic_stacktrace<Allocator>& a, basic_stacktrace<Allocator>& b)
+    noexcept(noexcept(a.swap(b)));
 \end{itemdecl}
 
 \begin{itemdescr}
@@ -2319,7 +2319,7 @@
 \indexlibrarymember{to_string}{basic_stacktrace}%
 \begin{itemdecl}
 template<class Allocator>
-string to_string(const basic_stacktrace<Allocator>& st);
+  string to_string(const basic_stacktrace<Allocator>& st);
 \end{itemdecl}
 
 \begin{itemdescr}