Remove trailing blank lines at ends of grammar productions.

Author: zygoloid

source/declarators.tex

@@ -2073,7 +2073,7 @@
     ctor-initializer\opt compound-statement\br
     function-try-block\br
     \terminal{= default ;}\br
-    \terminal{= delete ;}\br
+    \terminal{= delete ;}
 \end{bnf}
 
 Any informal reference to the body of a function should be interpreted as a reference to

source/expressions.tex

@@ -2474,7 +2474,7 @@
     \terminal{alignof (} type-id \terminal{)}\br
     noexcept-expression\br
     new-expression\br
-    delete-expression\br
+    delete-expression
 \end{bnf}
 
 \indextext{operator!indirection}%